<P>
Hi,<BR>
<BR>
I am Pramendra Singh. I am working on IPv6 implement=
ation for MVL_3.1,<BR>
which is a RTOS by SAMSUNG with Linux kernel 2.4.2=
0.<BR>
<BR>
I am working on TUNNEL module. For testing (conformance tes=
ting for<BR>
ipv6-over-ipv4 tunnel, RFC 2893),I am using FREE-BSD 5.4 as =
Tester Node and TAHI tool (v6eval 3.0) as testing tool.<BR>
<BR>
While =
testing I face some problem and I felt that this is due to the <BR>
probl=
ems in script. So, I modified accordingly.<BR>
<BR>
Here are the datils=
of changes made by me:<BR>
<BR>
1.In fragment.seq<BR>
<BR>
%ret==
vRecv($IF1,5,0,0,v6overv4_echo_request_LINK1_nut2tn_1300, v6overv4_echo_req=
uest_LINK1_nut2tn_1300_DF);<BR>
<BR>
/* I CHANGED UPPER LINE TO THE NEX=
T LINE */<BR>
<BR>
%ret=vRecv($IF1,5,0,0,v6overv4_echo_request_LINK1_=
nut2tn_1300_DF, v6overv4_echo_request_LINK1_nut2tn_1300);<BR>
<BR>
CLAR=
IFICATION: when TN is sending a packet to NUT on link0 with packet length 1=
280,NUT is replying on Link1 with a packet of length 1300 with DF bit SET. =
But origional script was recognizing it as a packet with length 1300 with D=
F bit NOTSET. After changing the script, script is getting the packet corre=
ctally.<BR>
<BR>
2.In fragment.def<BR>
<BR>
//<BR>
// ICMPv4 Pack=
et Too Big message<BR>
//<BR>
<BR>
FEM_icmp4_destination_unreachable =
(<BR>
icmp4_packet_too_big_LINK1_tn2nut_MTU_1420,<BR>=
_HETHER_tn2nut,<BR>
&nb=
sp; {<BR>
DF=1;<BR>
&nb=sp; _SRC(V4_OFFLINK_ADDRESS);<BR>
=
_DST(NUT_LINK1_V4_ADDRESS);<BR>
=
},<BR>
{<BR>
 =; Code=4;<BR>
&nbs=
p; Unused=1420;<BR>
&nbs=
p;payload=v4_orignal_packet_1450;/* I CHANGED HERE*/<BR>
=
<BR>
&nbs=
p; /* I CHANGED UPPER LINE TO THE THIS LINE */<BR>
=
payload=v6overv4_orignal_packet_1500;=
<BR>
<BR>
}<BR>
)<BR>
<BR>
&n=
bsp; <BR>
<BR>
<BR>
CLARIFICATION: In the origional sc=
ript when TN is sending a "Too Big" message with MTU 1420 to NUT =
on Link1, it sending it with the wrong Source Address and NUT was not=
able to change its MTU. But, further in the test TN is again sending a &qu=
ot;Too Big" message with MTU 1300 to NUT on Link1, and this time NUT M=
TU was being changed successfully.The only difference in both packets was t=
he payload and value of the variable "unused" in the packet defin=
ition. So, I just changed the payload to same one like it was in the "=
Too Big" message with MTU 1300<BR>
and kept the variable's value unc=
hanged. After making the change NUT MTU was being changed successfully and =
my test got passed.<BR>
<BR>
[ I gave prink statment in net/ipv4/route.=
c file in ip_rt_frag_needed() function and tried to find the reason for why=
NUT MTU was not being changed when TN is sending a "Too Big" mes=
sage with MTU 1420 to NUT on Link1. I find that the condition "r=
th->rt_src == iph->saddr" (line no 1071) was not=
being met and so it was not getting in the code and NUT MTU was not being =
changed. But when TN is sending a "Too Big" message with MTU 1300=
to NUT on Link1. I find that the condition <BR>
"rth->rt_src&nbs=
p; == iph->saddr" was being met and so it was getting in the co=
de and NUT MTU was being changed successfully.]<BR>
<BR>
please check i=
t whether changes made by me are correct or not and <BR>
at the same time=
wheter they are fulfilling the test conditions <BR>
correctally or not??=
<BR>
<BR>
Thanks<BR>
Pramendra Singh<BR>
Software Engineer,<BR>
L=
arson & Toubro Infotech<BR>
Church Street -2, Bangalore-2<BR>
India=
- 560001 <BR>
</P>
<br><br>
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