Hi Arman,
On Fri, Nov 7, 2014 at 10:41 PM, Arman Uguray <armansito@xxxxxxxxxxxx> wrote:
> This patch add support for handling ATT "Prepare Write" requests for the
> server role.
> ---
> src/shared/gatt-server.c | 142 +++++++++++++++++++++++++++++++++++++++++++++++
> src/shared/gatt-server.h | 3 +
> 2 files changed, 145 insertions(+)
>
> diff --git a/src/shared/gatt-server.c b/src/shared/gatt-server.c
> index e77acce..48a55e7 100644
> --- a/src/shared/gatt-server.c
> +++ b/src/shared/gatt-server.c
> @@ -40,6 +40,8 @@
> #define MIN(a, b) ((a) < (b) ? (a) : (b))
> #endif
>
> +#define DEFAULT_MAX_PREP_QUEUE_LEN 5
> +
> struct async_read_op {
> struct bt_gatt_server *server;
> uint8_t opcode;
> @@ -55,6 +57,22 @@ struct async_write_op {
> uint8_t opcode;
> };
>
> +struct prep_write_data {
> + struct bt_gatt_server *server;
> + uint8_t *value;
> + uint16_t handle;
> + uint16_t offset;
> + uint16_t length;
> +};
> +
> +static void prep_write_data_destroy(void *user_data)
> +{
> + struct prep_write_data *data = user_data;
> +
> + free(data->value);
> + free(data);
> +}
> +
> struct bt_gatt_server {
> struct gatt_db *db;
> struct bt_att *att;
> @@ -69,6 +87,10 @@ struct bt_gatt_server {
> unsigned int write_cmd_id;
> unsigned int read_id;
> unsigned int read_blob_id;
> + unsigned int prep_write_id;
> +
> + struct queue *prep_queue;
> + unsigned int max_prep_queue_len;
>
> struct async_read_op *pending_read_op;
> struct async_write_op *pending_write_op;
> @@ -91,6 +113,7 @@ static void bt_gatt_server_free(struct bt_gatt_server *server)
> bt_att_unregister(server->att, server->write_cmd_id);
> bt_att_unregister(server->att, server->read_id);
> bt_att_unregister(server->att, server->read_blob_id);
> + bt_att_unregister(server->att, server->prep_write_id);
>
> if (server->pending_read_op)
> server->pending_read_op->server = NULL;
> @@ -98,6 +121,8 @@ static void bt_gatt_server_free(struct bt_gatt_server *server)
> if (server->pending_write_op)
> server->pending_write_op->server = NULL;
>
> + queue_destroy(server->prep_queue, prep_write_data_destroy);
> +
> bt_att_unref(server->att);
> free(server);
> }
> @@ -922,6 +947,98 @@ static void read_blob_cb(uint8_t opcode, const void *pdu,
> handle_read_req(server, opcode, handle, offset);
> }
>
> +static void prep_write_cb(uint8_t opcode, const void *pdu,
> + uint16_t length, void *user_data)
> +{
> + struct bt_gatt_server *server = user_data;
> + struct prep_write_data *prep_data = NULL;
> + uint16_t handle = 0;
> + uint16_t offset;
> + struct gatt_db_attribute *attr;
> + uint8_t rsp_opcode;
> + uint8_t rsp_pdu[MAX(4, length)];
> + uint16_t rsp_len;
> + uint8_t ecode;
> + uint32_t perm;
> +
> + if (length < 4) {
> + ecode = BT_ATT_ERROR_INVALID_PDU;
> + goto error;
> + }
> +
> + if (queue_length(server->prep_queue) >= server->max_prep_queue_len) {
> + ecode = BT_ATT_ERROR_PREPARE_QUEUE_FULL;
> + goto error;
> + }
> +
> + handle = get_le16(pdu);
> + offset = get_le16(pdu + 2);
> +
> + attr = gatt_db_get_attribute(server->db, handle);
> + if (!attr) {
> + ecode = BT_ATT_ERROR_INVALID_HANDLE;
> + goto error;
> + }
> +
> + if (!gatt_db_attribute_get_permissions(attr, &perm)) {
> + ecode = BT_ATT_ERROR_INVALID_HANDLE;
> + goto error;
> + }
> +
> + /*
> + * TODO: The "Prepare Write" request requires security permission checks
> + * to be performed before the write is executed. I.e., we can't leave
> + * the permission check to the upper layer since we can't call
> + * gatt_db_write until the entire queue is atomically processed during
> + * an "Execute Write" request. Figure out how to make this check here.
> + */
> + if (!(perm & BT_ATT_PERM_WRITE)) {
> + ecode = BT_ATT_ERROR_WRITE_NOT_PERMITTED;
> + goto error;
> + }
> +
> + prep_data = new0(struct prep_write_data, 1);
> + if (!prep_data) {
> + ecode = BT_ATT_ERROR_INSUFFICIENT_RESOURCES;
> + goto error;
> + }
> +
> + prep_data->length = length - 4;
> + if (prep_data->length) {
> + prep_data->value = malloc(prep_data->length);
> + if (!prep_data->value) {
> + ecode = BT_ATT_ERROR_INSUFFICIENT_RESOURCES;
> + goto error;
> + }
> + }
> +
> + prep_data->server = server;
> + prep_data->handle = handle;
> + prep_data->offset = offset;
> + memcpy(prep_data->value, pdu + 4, prep_data->length);
> +
> + queue_push_tail(server->prep_queue, prep_data);
> +
> + /* Create the response */
> + rsp_len = length;
> + rsp_opcode = BT_ATT_OP_PREP_WRITE_RSP;
> + memcpy(rsp_pdu, pdu, rsp_len);
> +
> + goto done;
> +
> +error:
> + if (prep_data)
> + prep_write_data_destroy(prep_data);
> +
> + rsp_opcode = BT_ATT_OP_ERROR_RSP;
> + rsp_len = 4;
> + encode_error_rsp(opcode, handle, ecode, rsp_pdu);
> +
> +done:
> + bt_att_send(server->att, rsp_opcode, rsp_pdu, rsp_len, NULL, NULL,
> + NULL);
> +}
> +
> static void exchange_mtu_cb(uint8_t opcode, const void *pdu,
> uint16_t length, void *user_data)
> {
> @@ -1015,6 +1132,13 @@ static bool gatt_server_register_att_handlers(struct bt_gatt_server *server)
> if (!server->read_blob_id)
> return false;
>
> + /* Prepare Write Request */
> + server->prep_write_id = bt_att_register(server->att,
> + BT_ATT_OP_PREP_WRITE_REQ,
> + prep_write_cb, server, NULL);
> + if (!server->prep_write_id)
> + return false;
> +
> return true;
> }
>
> @@ -1033,6 +1157,13 @@ struct bt_gatt_server *bt_gatt_server_new(struct gatt_db *db,
> server->db = db;
> server->att = bt_att_ref(att);
> server->mtu = MAX(mtu, BT_ATT_DEFAULT_LE_MTU);
> + server->max_prep_queue_len = DEFAULT_MAX_PREP_QUEUE_LEN;
> +
> + server->prep_queue = queue_new();
> + if (!server->prep_queue) {
> + bt_gatt_server_free(server);
> + return NULL;
> + }
>
> if (!gatt_server_register_att_handlers(server)) {
> bt_gatt_server_free(server);
> @@ -1078,6 +1209,17 @@ bool bt_gatt_server_set_debug(struct bt_gatt_server *server,
> return true;
> }
>
> +bool bt_gatt_server_set_max_prep_queue_length(struct bt_gatt_server *server,
> + unsigned int length)
> +{
> + if (!server || !length)
> + return false;
> +
> + server->max_prep_queue_len = length;
> +
> + return true;
> +}
> +
> bool bt_gatt_server_send_notification(struct bt_gatt_server *server,
> uint16_t handle, const uint8_t *value,
> uint16_t length)
> diff --git a/src/shared/gatt-server.h b/src/shared/gatt-server.h
> index 0e480e1..a95613c 100644
> --- a/src/shared/gatt-server.h
> +++ b/src/shared/gatt-server.h
> @@ -40,6 +40,9 @@ bool bt_gatt_server_set_debug(struct bt_gatt_server *server,
> void *user_data,
> bt_gatt_server_destroy_func_t destroy);
>
> +bool bt_gatt_server_set_max_prep_queue_length(struct bt_gatt_server *server,
> + unsigned int length);
Perhaps we should leave this API for later, Im not really sure if this
will be ever used except perhaps for the TS in that case perhaps we
should find a shorter name.
> bool bt_gatt_server_send_notification(struct bt_gatt_server *server,
> uint16_t handle, const uint8_t *value,
> uint16_t length);
> --
> 2.1.0.rc2.206.gedb03e5
>
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--
Luiz Augusto von Dentz
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