Bluetooth: GATT: Expose ATT error codes to application callbacks

Introduce BT_GATT_ERR macro to make it possible for application
callbacks to return exact ATT error codes.

Change-Id: I971536508e75036fbddc40b3f33e5201e11940bc
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

8 files changed, 53 insertions, 49 deletions

diff --git a/drivers/nble/gatt.c b/drivers/nble/gatt.c
index 897c2c639..0aec22674 100644
--- a/drivers/nble/gatt.c
+++ b/drivers/nble/gatt.c
@@ -301,7 +301,7 @@ int bt_gatt_attr_read_ccc(struct bt_conn *conn,
 			  const struct bt_gatt_attr *attr, void *buf,
 			  uint16_t len, uint16_t offset)
 {
-	return -ENOSYS;
+	return BT_GATT_ERR(BT_ATT_ERR_NOT_SUPPORTED);
 }
 
 int bt_gatt_attr_write_ccc(struct bt_conn *conn,
@@ -312,11 +312,11 @@ int bt_gatt_attr_write_ccc(struct bt_conn *conn,
 	const uint16_t *data = buf;
 
 	if (offset > sizeof(*data)) {
-		return -EINVAL;
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_OFFSET);
 	}
 
 	if (offset + len > sizeof(*data)) {
-		return -EFBIG;
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_ATTRIBUTE_LEN);
 	}
 
 	/* We expect to receive this only when the has really changed */
@@ -346,14 +346,14 @@ int bt_gatt_attr_read_cud(struct bt_conn *conn,
 			  const struct bt_gatt_attr *attr, void *buf,
 			  uint16_t len, uint16_t offset)
 {
-	return -ENOSYS;
+	return BT_GATT_ERR(BT_ATT_ERR_NOT_SUPPORTED);
 }
 
 int bt_gatt_attr_read_cpf(struct bt_conn *conn,
 			  const struct bt_gatt_attr *attr, void *buf,
 			  uint16_t len, uint16_t offset)
 {
-	return -ENOSYS;
+	return BT_GATT_ERR(BT_ATT_ERR_NOT_SUPPORTED);
 }
 
 int bt_gatt_notify(struct bt_conn *conn, const struct bt_gatt_attr *attr,
diff --git a/include/bluetooth/gatt.h b/include/bluetooth/gatt.h
index 7e78992fa..d57b1c433 100644
--- a/include/bluetooth/gatt.h
+++ b/include/bluetooth/gatt.h
@@ -88,6 +88,17 @@ extern "C" {
  */
 #define BT_GATT_FLUSH_SYNC			0x01
 
+/**  @def BT_GATT_ERR
+  *  @brief Construct error return value for attribute read, write and
+  *         flush callbacks.
+  *
+  *  @param _att_err ATT error code
+  *
+  *  @return Appropriate error code for the attribute callbacks.
+  *
+  */
+#define BT_GATT_ERR(_att_err)                  (-(_att_err))
+
 /** @brief GATT Attribute structure. */
 struct bt_gatt_attr {
 	/** Attribute UUID */
diff --git a/net/bluetooth/att.c b/net/bluetooth/att.c
index 5f2e68bd5..351d86929 100644
--- a/net/bluetooth/att.c
+++ b/net/bluetooth/att.c
@@ -571,16 +571,11 @@ static uint8_t err_to_att(int err)
 {
 	BT_DBG("%d", err);
 
-	switch (err) {
-	case -EINVAL:
-		return BT_ATT_ERR_INVALID_OFFSET;
-	case -EFBIG:
-		return BT_ATT_ERR_INVALID_ATTRIBUTE_LEN;
-	case -EACCES:
-		return BT_ATT_ERR_ENCRYPTION_KEY_SIZE;
-	default:
-		return BT_ATT_ERR_UNLIKELY;
+	if (err < 0 && err >= -0xff) {
+		return -err;
 	}
+
+	return BT_ATT_ERR_UNLIKELY;
 }
 
 struct read_type_data {
diff --git a/net/bluetooth/gatt.c b/net/bluetooth/gatt.c
index 74cd5c94d..7c952c569 100644
--- a/net/bluetooth/gatt.c
+++ b/net/bluetooth/gatt.c
@@ -316,11 +316,11 @@ int bt_gatt_attr_write_ccc(struct bt_conn *conn,
 	size_t i;
 
 	if (offset > sizeof(*data)) {
-		return -EINVAL;
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_OFFSET);
 	}
 
 	if (offset + len > sizeof(*data)) {
-		return -EFBIG;
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_ATTRIBUTE_LEN);
 	}
 
 	if (bt_keys_find_addr(&conn->le.dst))
@@ -348,7 +348,7 @@ int bt_gatt_attr_write_ccc(struct bt_conn *conn,
 
 		if (i == ccc->cfg_len) {
 			BT_WARN("No space to store CCC cfg");
-			return -ENOMEM;
+			return BT_GATT_ERR(BT_ATT_ERR_INSUFFICIENT_RESOURCES);
 		}
 	}
 
diff --git a/samples/bluetooth/peripheral/src/main.c b/samples/bluetooth/peripheral/src/main.c
index b13b7ad15..08ab9a494 100644
--- a/samples/bluetooth/peripheral/src/main.c
+++ b/samples/bluetooth/peripheral/src/main.c
@@ -141,7 +141,7 @@ static int write_ct(struct bt_conn *conn, const struct bt_gatt_attr *attr,
 	uint8_t *value = attr->user_data;
 
 	if (offset + len > sizeof(ct)) {
-		return -EINVAL;
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_OFFSET);
 	}
 
 	memcpy(value + offset, buf, len);
@@ -198,7 +198,7 @@ static int write_vnd(struct bt_conn *conn, const struct bt_gatt_attr *attr,
 	uint8_t *value = attr->user_data;
 
 	if (offset + len > sizeof(vnd_value)) {
-		return -EINVAL;
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_OFFSET);
 	}
 
 	memcpy(value + offset, buf, len);
@@ -233,7 +233,7 @@ static int write_long_vnd(struct bt_conn *conn,
 	struct vnd_long_value *value = attr->user_data;
 
 	if (offset + len > sizeof(value->buf)) {
-		return -EINVAL;
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_OFFSET);
 	}
 
 	/* Copy to buffer */
@@ -258,7 +258,7 @@ static int flush_long_vnd(struct bt_conn *conn,
 		return 0;
 	}
 
-	return -EINVAL;
+	return BT_GATT_ERR(BT_ATT_ERR_UNLIKELY);
 }
 
 static const struct bt_uuid_128 vnd_long_uuid = BT_UUID_INIT_128(
@@ -286,7 +286,7 @@ static int write_signed(struct bt_conn *conn, const struct bt_gatt_attr *attr,
 	uint8_t *value = attr->user_data;
 
 	if (offset + len > sizeof(signed_value)) {
-		return -EINVAL;
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_OFFSET);
 	}
 
 	memcpy(value + offset, buf, len);
diff --git a/samples/bluetooth/peripheral_csc/src/main.c b/samples/bluetooth/peripheral_csc/src/main.c
index eeaa28055..04f985f67 100644
--- a/samples/bluetooth/peripheral_csc/src/main.c
+++ b/samples/bluetooth/peripheral_csc/src/main.c
@@ -238,12 +238,11 @@ static int write_ctrl_point(struct bt_conn *conn,
 	int i;
 
 	if (!ctrl_point_configured) {
-		/* TODO: Return CSC_ERR_CCC_CONFIG */
-		return -EINVAL;
+		return BT_GATT_ERR(CSC_ERR_CCC_CONFIG);
 	}
 
 	if (!len) {
-		return -EINVAL;
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_ATTRIBUTE_LEN);
 	}
 
 	switch (req->op) {
diff --git a/samples/bluetooth/peripheral_esp/src/main.c b/samples/bluetooth/peripheral_esp/src/main.c
index 3dbc10b24..a55741060 100644
--- a/samples/bluetooth/peripheral_esp/src/main.c
+++ b/samples/bluetooth/peripheral_esp/src/main.c
@@ -328,15 +328,16 @@ static int write_temp_trigger_setting(struct bt_conn *conn,
 				      uint16_t offset)
 {
 	const struct write_es_trigger_setting_req *req = buf;
+	const struct es_trigger_setting_reference *ref;
 	struct temperature_sensor *sensor = attr->user_data;
+	uint16_t ref_val;
 
 	if (!len) {
-		return -EFBIG;
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_ATTRIBUTE_LEN);
 	}
 
 	if (req->condition > 0x09) {
-		/* TODO: Return ESS_ERR_COND_NOT_SUPP */
-		return -EINVAL;
+		return BT_GATT_ERR(ESS_ERR_COND_NOT_SUPP);
 	}
 
 	switch (req->condition) {
@@ -345,7 +346,7 @@ static int write_temp_trigger_setting(struct bt_conn *conn,
 		/* fallthrough */
 	case ESS_VALUE_CHANGED:
 		if (len != sizeof(sensor->condition)) {
-			return -EINVAL;
+			return BT_GATT_ERR(BT_ATT_ERR_INVALID_ATTRIBUTE_LEN);
 		}
 
 		sensor->condition = req->condition;
@@ -355,30 +356,28 @@ static int write_temp_trigger_setting(struct bt_conn *conn,
 		/* fallthrough */
 	case ESS_NO_LESS_THAN_SPECIFIED_TIME:
 		if (len != sizeof(struct es_trigger_setting_seconds)) {
-			return -EINVAL;
+			return BT_GATT_ERR(BT_ATT_ERR_INVALID_ATTRIBUTE_LEN);
 		}
 
 		sensor->condition = req->condition;
 		sensor->seconds = le24_to_int(req->operand);
 		break;
 	/* Reference temperature */
-	default: {
-			const struct es_trigger_setting_reference *req = buf;
-			uint16_t ref_val = sys_le16_to_cpu(req->ref_val);
-
-			if (len != sizeof(*req)) {
-				return -EINVAL;
-			}
+	default:
+		if (len != sizeof(*ref)) {
+			return BT_GATT_ERR(BT_ATT_ERR_INVALID_ATTRIBUTE_LEN);
+		}
 
-			if (sensor->lower_limit > ref_val ||
-			    sensor->upper_limit < ref_val) {
-				/* TODO: Return ERR_OUT_OF_RANGE */
-				return -EINVAL;
-			}
+		ref = buf;
+		ref_val = sys_le16_to_cpu(ref->ref_val);
 
-			sensor->condition = req->condition;
-			sensor->ref_val = ref_val;
+		if (sensor->lower_limit > ref_val ||
+		    sensor->upper_limit < ref_val) {
+			return BT_GATT_ERR(BT_ATT_ERR_OUT_OF_RANGE);
 		}
+
+		sensor->condition = req->condition;
+		sensor->ref_val = ref_val;
 	}
 
 	return len;
diff --git a/tests/bluetooth/tester/src/gatt.c b/tests/bluetooth/tester/src/gatt.c
index 35f743403..ee0a18c34 100644
--- a/tests/bluetooth/tester/src/gatt.c
+++ b/tests/bluetooth/tester/src/gatt.c
@@ -231,7 +231,7 @@ static int read_value(struct bt_conn *conn, const struct bt_gatt_attr *attr,
 
 	if ((attr->perm & GATT_PERM_ENC_READ_MASK) &&
 	    (value->enc_key_size > bt_conn_enc_key_size(conn))) {
-		return -EACCES;
+		return BT_GATT_ERR(BT_ATT_ERR_ENCRYPTION_KEY_SIZE);
 	}
 
 	return bt_gatt_attr_read(conn, attr, buf, len, offset, value->data,
@@ -245,7 +245,7 @@ static int write_value(struct bt_conn *conn, const struct bt_gatt_attr *attr,
 
 	if ((attr->perm & GATT_PERM_ENC_WRITE_MASK) &&
 	    (value->enc_key_size > bt_conn_enc_key_size(conn))) {
-		return -EACCES;
+		return BT_GATT_ERR(BT_ATT_ERR_ENCRYPTION_KEY_SIZE);
 	}
 
 	/*
@@ -254,11 +254,11 @@ static int write_value(struct bt_conn *conn, const struct bt_gatt_attr *attr,
 	 * «Invalid Offset».
 	 */
 	if (offset > value->len) {
-		return -EINVAL;
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_OFFSET);
 	}
 
 	if (offset + len > value->len) {
-		return -EFBIG;
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_ATTRIBUTE_LEN);
 	}
 
 	memcpy(value->prep_data + offset, buf, len);
@@ -281,7 +281,7 @@ static int flush_value(struct bt_conn *conn,
 		return 0;
 	}
 
-	return -EINVAL;
+	return BT_GATT_ERR(BT_ATT_ERR_UNLIKELY);
 }
 
 static struct bt_gatt_attr chr = BT_GATT_CHARACTERISTIC(NULL, 0);