hw/bt: Fixup problems with BT get capabilities code

Commit fb457c95 had a few issues chief of which being incorrectly accessing
IPMI response buffer.

IPMI response to Get BT Interface Capabilities Command documented in 22.10
of IPMI spec v2.0 rev 1.1, table 22, page 280

Signed-off-by: Cyril Bur <cyril.bur@au1.ibm.com>
[stewart@linux.vnet.ibm.com: add spec to commit message]
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 13 insertions, 12 deletions

diff --git a/hw/bt.c b/hw/bt.c
index b33640e..550469d 100644
--- a/hw/bt.c
+++ b/hw/bt.c
@@ -109,8 +109,8 @@ struct bt_msg {
 
 struct bt_caps {
 	uint8_t num_requests;
-	uint8_t input_buf_len;
-	uint8_t output_buf_len;
+	uint16_t input_buf_len;
+	uint16_t output_buf_len;
 	uint8_t msg_timeout;
 	uint8_t num_retries;
 };
@@ -164,27 +164,28 @@ static void get_bt_caps_complete(struct ipmi_msg *msg)
 		goto out;
 	}
 
-	if (msg->data[3] + 1 != BT_FIFO_LEN) {
-		BT_DBG("Got a input buffer len (%d) cap which differs from the default\n",
-				msg->data[3]);
+	if (msg->data[1] + 1 != BT_FIFO_LEN) {
+		BT_DBG("Got a input buffer len (%u) cap which differs from the default\n",
+				msg->data[1]);
 		goto out;
 	}
 
-	if (msg->data[4] + 1 != BT_FIFO_LEN) {
-		BT_DBG("Got a output buffer len (%d) cap which differs from the default\n",
-				msg->data[4]);
+	if (msg->data[2] + 1 != BT_FIFO_LEN) {
+		BT_DBG("Got a output buffer len (%u) cap which differs from the default\n",
+				msg->data[2]);
 		goto out;
 	}
 
-	memcpy(&bt.caps, msg->data, sizeof(struct bt_caps));
-
 	/*
 	 * IPMI Spec says that the value for buffer sizes are:
 	 * "the largest value allowed in first byte"
 	 * Therefore we want to add one to what we get
 	 */
-	bt.caps.input_buf_len++;
-	bt.caps.output_buf_len++;
+	bt.caps.num_requests = msg->data[0];
+	bt.caps.input_buf_len = msg->data[1] + 1;
+	bt.caps.output_buf_len = msg->data[2] + 1;
+	bt.caps.msg_timeout = msg->data[3];
+	bt.caps.num_retries = msg->data[4];
 	BT_DBG("BMC BT capabilities received:\n");
 	BT_DBG("buffer sizes: %d input %d output\n",
 			bt.caps.input_buf_len, bt.caps.output_buf_len);