From e1cc7078cc48c9ca081c0c5f4acc8d15212a1a06 Mon Sep 17 00:00:00 2001
From: scipio <scipio>
Date: Thu, 19 Apr 2007 22:45:47 +0000
Subject: [PATCH] Bug fix from John Regehr.

---
 tos/lib/serial/SerialDispatcherP.nc | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/tos/lib/serial/SerialDispatcherP.nc b/tos/lib/serial/SerialDispatcherP.nc
index cc85a3f3..fdcb5b6f 100644
--- a/tos/lib/serial/SerialDispatcherP.nc
+++ b/tos/lib/serial/SerialDispatcherP.nc
@@ -102,13 +102,21 @@ implementation {
       return EBUSY;
     }
 
-    sendState = SEND_STATE_DATA;
-    sendId = id;
-    sendCancelled = FALSE;
     atomic {
+      sendIndex = call PacketInfo.offset[id]();
+      if (sendIndex > sizeof(message_header_t)) {
+	return ESIZE;
+      }
+      
       sendError = SUCCESS;
       sendBuffer = (uint8_t*)msg;
-      sendIndex = call PacketInfo.offset[id]();
+      sendState = SEND_STATE_DATA;
+      sendId = id;
+      sendCancelled = FALSE;
+      // If something we're starting past the header, something is wrong
+      // Bug fix from John Regehr
+
+
       // sendLen is where in the buffer the packet stops.
       // This is the length of the packet, plus its start point
       sendLen = call PacketInfo.dataLinkLength[id](msg, len) + sendIndex;
-- 
2.39.2