Ticket #342: routing_bug

From - Thu Feb  6 11:10:27 2003
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Date: Thu, 6 Feb 2003 09:09:24 -0600
Message-ID: <IGEBLLKBHLNKJHDJNDEAOEIKCIAA.mikes@poliac.com>
From: "Mike Siers" <mikes@poliac.com>
To: rtems-users@oarcorp.com
Subject: Network Routing Bug
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Hi All,
I think I found a small bug in the RTEMS version of the function 
m_copyback().  I am using the rtems-ss-20021118 snapshot.

The RTEMS version of the m_copyback is changing the m_len value of
the mbuf.  I looked into the source from another BSD system and
the mbuf length is not changed inside this function.  

The m_copyback function is only being used in the net/rtsock.c file.
So I think this problem is only visable under certain routing table 
conditions.  

Below is my patch to fix the problem. The uipc_mbuf.c file is located
in the cpukit/libnetworking/kern directory.  Please review and let 
me know if you think this the correct fix.

Thanks
Mike Siers

==============================================
--- uipc_mbuf.c Sat Nov  2 10:27:43 2002
+++ uipc_mbuf.new       Thu Feb  6 08:50:46 2003
@@ -755,7 +755,7 @@
                off = 0;
                totlen += mlen;
                if (len == 0) {
-                       m->m_len = mlen;
+                       /* m->m_len = mlen; */
                        break;
                }
                if (m->m_next == 0) {
@@ -767,7 +767,7 @@
                        n->m_len = min(MLEN, len);
                        m->m_next = n;
                }
-               m->m_len = mlen;
+               /* m->m_len = mlen; */
                m = m->m_next;
        }
 /*out:*/