[cgutman] 57169: [LWIP] - Fix broken handling of partial receives

Author: cgutman
Date: Sun Aug 26 22:24:49 2012
New Revision: 57169

URL: http://svn.reactos.org/svn/reactos?rev=57169&view=rev
Log:
[LWIP]
- Fix broken handling of partial receives

Modified:
    trunk/reactos/lib/drivers/lwip/src/include/rosip.h
    trunk/reactos/lib/drivers/lwip/src/rostcp.c

Modified: trunk/reactos/lib/drivers/lwip/src/include/rosip.h
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/drivers/lwip/src/inclu…
==============================================================================
--- trunk/reactos/lib/drivers/lwip/src/include/rosip.h [iso-8859-1] (original)
+++ trunk/reactos/lib/drivers/lwip/src/include/rosip.h [iso-8859-1] Sun Aug 26 22:24:49
2012
@@ -15,6 +15,7 @@
 typedef struct _QUEUE_ENTRY
 {
     struct pbuf *p;
+    ULONG Offset;
     LIST_ENTRY ListEntry;
 } QUEUE_ENTRY, *PQUEUE_ENTRY;
 

Modified: trunk/reactos/lib/drivers/lwip/src/rostcp.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/drivers/lwip/src/rostc…
==============================================================================
--- trunk/reactos/lib/drivers/lwip/src/rostcp.c [iso-8859-1] (original)
+++ trunk/reactos/lib/drivers/lwip/src/rostcp.c [iso-8859-1] Sun Aug 26 22:24:49 2012
@@ -60,6 +60,7 @@
 
     qp = (PQUEUE_ENTRY)ExAllocateFromNPagedLookasideList(&QueueEntryLookasideList);
     qp->p = p;
+    qp->Offset = 0;
 
     ExInterlockedInsertTailList(&Connection->PacketQueue, &qp->ListEntry,
&Connection->Lock);
 }
@@ -82,9 +83,10 @@
 {
     PQUEUE_ENTRY qp;
     struct pbuf* p;
-    NTSTATUS Status = STATUS_PENDING;
-    UINT ReadLength, ExistingDataLength;
+    NTSTATUS Status;
+    UINT ReadLength, PayloadLength;
     KIRQL OldIrql;
+    PUCHAR Payload;
 
     (*Received) = 0;
 
@@ -95,49 +97,53 @@
         while ((qp = LibTCPDequeuePacket(Connection)) != NULL)
         {
             p = qp->p;
-            ExistingDataLength = (*Received);
+
+            /* Calculate the payload first */
+            Payload = p->payload;
+            Payload += qp->Offset;
+            PayloadLength = p->len;
+            PayloadLength -= qp->Offset;
+
+            /* Check if we're reading the whole buffer */
+            ReadLength = MIN(PayloadLength, RecvLen);
+            if (ReadLength != PayloadLength)
+            {
+                /* Save this one for later */
+                qp->Offset += ReadLength;
+                InsertHeadList(&Connection->PacketQueue, &qp->ListEntry);
+                qp = NULL;
+            }
+
+            UnlockObject(Connection, OldIrql);
+
+            /* Return to a lower IRQL because the receive buffer may be pageable memory
*/
+            RtlCopyMemory(RecvBuffer,
+                          Payload,
+                          ReadLength);
+
+            LockObject(Connection, &OldIrql);
+
+            /* Update trackers */
+            RecvLen -= ReadLength;
+            RecvBuffer += ReadLength;
+            (*Received) += ReadLength;
+
+            if (qp != NULL)
+            {
+                /* Use this special pbuf free callback function because we're outside
tcpip thread */
+                pbuf_free_callback(qp->p);
+
+                ExFreeToNPagedLookasideList(&QueueEntryLookasideList, qp);
+            }
+            else
+            {
+                /* If we get here, it means we've filled the buffer */
+                ASSERT(RecvLen == 0);
+            }
 
             Status = STATUS_SUCCESS;
 
-            ReadLength = MIN(p->tot_len, RecvLen);
-            if (ReadLength != p->tot_len)
-            {
-                if (ExistingDataLength)
-                {
-                    /* The packet was too big but we used some data already so give it
another shot later */
-                    InsertHeadList(&Connection->PacketQueue,
&qp->ListEntry);
-                    break;
-                }
-                else
-                {
-                    /* The packet is just too big to fit fully in our buffer, even when
empty so
-                     * return an informative status but still copy all the data we can
fit.
-                     */
-                    Status = STATUS_BUFFER_OVERFLOW;
-                }
-            }
-
-            UnlockObject(Connection, OldIrql);
-
-            /* Return to a lower IRQL because the receive buffer may be pageable memory
*/
-            for (; (*Received) < ReadLength + ExistingDataLength; (*Received) +=
p->len, p = p->next)
-            {
-                RtlCopyMemory(RecvBuffer + (*Received), p->payload, p->len);
-            }
-
-            LockObject(Connection, &OldIrql);
-
-            RecvLen -= ReadLength;
-
-            /* Use this special pbuf free callback function because we're outside
tcpip thread */
-            pbuf_free_callback(qp->p);
-
-            ExFreeToNPagedLookasideList(&QueueEntryLookasideList, qp);
-
             if (!RecvLen)
-                break;
-
-            if (Status != STATUS_SUCCESS)
                 break;
         }
     }
@@ -196,6 +202,8 @@
 InternalRecvEventHandler(void *arg, PTCP_PCB pcb, struct pbuf *p, const err_t err)
 {
     PCONNECTION_ENDPOINT Connection = arg;
+    struct pbuf *pb;
+    ULONG RecvLen;
 
     /* Make sure the socket didn't get closed */
     if (!arg)
@@ -208,9 +216,19 @@
 
     if (p)
     {
-        LibTCPEnqueuePacket(Connection, p);
-
-        tcp_recved(pcb, p->tot_len);
+        pb = p;
+        RecvLen = 0;
+        while (pb != NULL)
+        {
+            /* Enqueue this buffer */
+            LibTCPEnqueuePacket(Connection, pb);
+            RecvLen += pb->len;
+
+            /* Advance and unchain the buffer */
+            pb = pbuf_dechain(pb);;
+        }
+
+        tcp_recved(pcb, RecvLen);
 
         TCPRecvEventHandler(arg);
     }