Changeset 11436 in vbox for trunk

Timestamp:

Aug 14, 2008 6:26:29 PM (17 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

34788

Message:

PCNet: Added check of incoming frame size. Frames over 1514 bytes (1518 with vlan tag) are discarded.

File:

• trunk/src/VBox/Devices/Network/DevPCNet.cpp (modified) (2 diffs)

trunk/src/VBox/Devices/Network/DevPCNet.cpp

@@ -4386 +4386 @@
     PCNetState *pThis = INETWORKPORT_2_DATA(pInterface);
     int         rc;
+    static bool firstBigFrameLoss = true;
 
     STAM_PROFILE_ADV_START(&pThis->StatReceive, a);
@@ -4391 +4392 @@
     AssertReleaseRC(rc);
 
-    if (cb > 70) /* unqualified guess */
-        pThis->Led.Asserted.s.fReading = pThis->Led.Actual.s.fReading = 1;
-    pcnetReceiveNoSync(pThis, (const uint8_t *)pvBuf, cb);
-    pThis->Led.Actual.s.fReading = 0;
+    /*
+     * Determine max ethernet frame size with vlan tag (TPID == 0x8100) or without it
+     * (excluding CRC which is not transferred).
+     * It consists of 14-byte header [+ 4-byte vlan tag] + 1500-byte body.
+     */
+    register maxFrameSize = ((uint16_t*)pvBuf)[6] == 0x81 ? 1518 : 1514;
+    if (RT_UNLIKELY(cb > maxFrameSize))
+    {
+        if (RT_UNLIKELY(firstBigFrameLoss))
+        {
+            firstBigFrameLoss = false;
+            Log(("#%d Received frame exceeds max size (%u > %u). "
+                 "Further frame losses will be reported at level5\n",
+                 PCNET_INST_NR, (unsigned)cb, (unsigned)maxFrameSize));
+        }
+        else
+            Log5(("#%d Received frame exceeds max size (%u > %u)\n",
+                  PCNET_INST_NR, (unsigned)cb, (unsigned)maxFrameSize));
+    }
+    else
+    {
+        if (cb > 70) /* unqualified guess */
+            pThis->Led.Asserted.s.fReading = pThis->Led.Actual.s.fReading = 1;
+        pcnetReceiveNoSync(pThis, (const uint8_t *)pvBuf, cb);
+        pThis->Led.Actual.s.fReading = 0;
+    }
 
     PDMCritSectLeave(&pThis->CritSect);