Ticket #2594: BufferQueue.cpp.1.diff

src/add-ons/kernel/network/protocols/tcp/BufferQueue.cpp

@@ -100 +100 @@
         fLastSequence = sequence + buffer->size;
 
     if (fFirstSequence > sequence) {
+        ASSERT(fFirstSequence - sequence < buffer->size); // XXX
+        //XXX remove_header(), remove_trailer() do not remove any bytes from the buffer
+        //when passed with a byte count larger than the buffer size.
+
         // this buffer contains data that is already long gone - trim it
         gBufferModule->remove_header(buffer, fFirstSequence - sequence);
         sequence = fFirstSequence;
+        buffer->sequence = fFirstSequence;
+        // XXX
+        // A similar line is near the top of this function.
     }
 
     // find the place where to insert the buffer into the queue
@@ -129 +136 @@
                 gBufferModule->free(buffer);
                 buffer = NULL;
             } else {
+                fNumBytes -= previous->size;
                 fList.Remove(previous);
                 gBufferModule->free(previous);
+                //XXX fContiguousBytes will probably not be correctly maintained
+                //if we got here to remove the first buffer in the queue
             }
         } else if (tcp_sequence(previous->sequence + previous->size) > sequence) {
-            gBufferModule->remove_header(buffer,
-                previous->sequence + previous->size - sequence);
+            if (previous->sequence + previous->size - sequence >= buffer->size) {
+                gBufferModule->free(buffer);
+                buffer = NULL;
+            } else {
+                gBufferModule->remove_header(buffer,
+                    previous->sequence + previous->size - sequence);
+            }
         }
     }
 
-    if (buffer != NULL && next != NULL
+    while (buffer != NULL && next != NULL
         && tcp_sequence(sequence + buffer->size) > next->sequence) {
         // we already have at least part of this data
         if (tcp_sequence(next->sequence + next->size) < sequence + buffer->size) {
             net_buffer *remove = next;
             next = (net_buffer *)next->link.next;
 
+            fNumBytes -= remove->size;
             fList.Remove(remove);
             gBufferModule->free(remove);
         } else {
+            ASSERT(sequence + buffer->size - next->sequence < buffer->size);    //XXX
             gBufferModule->remove_trailer(buffer,
                 sequence + buffer->size - next->sequence);
         }
@@ -215 +232 @@
         } else {
             // remove the header as far as needed
             size_t size = sequence - buffer->sequence;
+            //XXX
+            ASSERT(size <= sequence - buffer->sequence);
             gBufferModule->remove_header(buffer, size);
 
             buffer->sequence += size;
@@ -345 +364 @@
             iterator.Remove();
             gBufferModule->free(source);
         } else {
+            //XXX remove_header does not remove anything when told to remove more bytes than the the buffer's size
+            ASSERT(size <= source->size);
             gBufferModule->remove_header(source, size);
             source->sequence += size;
         }
@@ -377 +398 @@
     return fContiguousBytes + fFirstSequence - sequence;
 }
 
+
 void
 BufferQueue::SetPushPointer()
 {
@@ -385 +407 @@
     else
         fPushPointer = fList.Tail()->sequence + fList.Tail()->size;
 }
+
+
+/*! Sanity check
+*/
+void
+BufferQueue::Verify()
+{
+    ASSERT(Available() == 0 || fList.First() != NULL); 
+
+    if (fList.First() == NULL)
+        return;
+
+    SegmentList::Iterator it = fList.GetIterator();
+    net_buffer *nb;
+    size_t sum=0;
+    while ( (nb = it.Next()) != NULL )
+        sum += nb->size;
+
+    if (sum != fNumBytes)
+        TRACE(("BufferQueue@%p::Verify(): %d=sum != fNumBytes=%d\n", this, sum, fNumBytes));
+    ASSERT(sum == fNumBytes);
+}
+
+
+void
+BufferQueue::Dump()
+{
+    SegmentList::Iterator it = fList.GetIterator();
+    net_buffer *nb; 
+
+    TRACE(("BufferQueue@%p::Dump() >>>\n", this));
+    while ( (nb = it.Next()) != NULL )
+        TRACE(("BufferQueue@%p::Dump(): sequence 0x%x, size 0x%x\n", this, (uint32)nb->sequence, nb->size));
+    TRACE(("BufferQueue@%p::Dump() <<<\n", this));
+}
+

src/add-ons/kernel/network/protocols/tcp/BufferQueue.h

@@ -36 +36 @@
             size_t          Available() const { return fContiguousBytes; }
             size_t          Available(tcp_sequence sequence) const;
 
-    inline  size_t          PushedData() const;
+            inline  size_t          PushedData() const;
             void            SetPushPointer();
 
             size_t          Used() const { return fNumBytes; }
@@ -51 +51 @@
             tcp_sequence    NextSequence() const
                                 { return fFirstSequence + fContiguousBytes; }
 
+            void            Verify();
+            void            Dump();
+
 private:
     SegmentList             fList;
     size_t                  fMaxBytes;