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>

diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index e7e12cf..928148c 100644 (file)
--- 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 {