hyperv: Add buffer for extended info after the RNDIS response message.

In some response messages, there may be some extended info after the
message.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 10 deletions

diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index e7e12cfbbf37..928148cc3220 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -32,16 +32,19 @@
 #include "hyperv_net.h"
 
 
+#define RNDIS_EXT_LEN 100
 struct rndis_request {
         struct list_head list_ent;
         struct completion  wait_event;
 
+        struct rndis_message response_msg;
         /*
-         * FIXME: We assumed a fixed size response here. If we do ever need to
-         * handle a bigger response, we can either define a max response
-         * message or add a response buffer variable above this field
+         * The buffer for extended info after the RNDIS response message. It's
+         * referenced based on the data offset in the RNDIS message. Its size
+         * is enough for current needs, and should be sufficient for the near
+         * future.
          */
-        struct rndis_message response_msg;
+        u8 response_ext[RNDIS_EXT_LEN];
 
         /* Simplify allocation by having a netvsc packet inline */
         struct hv_netvsc_packet pkt;
@@ -50,12 +53,10 @@ struct rndis_request {
 
         struct rndis_message request_msg;
         /*
-         * The buffer for the extended info after the RNDIS message. It's
-         * referenced based on the data offset in the RNDIS message. Its size
-         * is enough for current needs, and should be sufficient for the near
-         * future.
+         * The buffer for the extended info after the RNDIS request message.
+         * It is referenced and sized in a similar way as response_ext.
          */
-        u8 ext[100];
+        u8 request_ext[RNDIS_EXT_LEN];
 };
 
 static void rndis_filter_send_completion(void *ctx);
@@ -274,7 +275,8 @@ static void rndis_filter_receive_response(struct rndis_device *dev,
         spin_unlock_irqrestore(&dev->request_lock, flags);
 
         if (found) {
-                if (resp->msg_len <= sizeof(struct rndis_message)) {
+                if (resp->msg_len <=
+                    sizeof(struct rndis_message) + RNDIS_EXT_LEN) {
                         memcpy(&request->response_msg, resp,
                                resp->msg_len);
                 } else {