<html>
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<div class="moz-cite-prefix">Hi Musab,<br>
<br>
First I would like to let you know that we are now <a
href="http://www.openoverlayrouter.org/">OpenOverlayRouter</a>.
If possible use the new OOR mailing lists to contact us from now
on :)<br>
<br>
I will try to give you some answers inline:<br>
<br>
On 01/03/16 18:40, MUSAB MUHAMMAD wrote:<br>
</div>
<blockquote
cite="mid:532046786.1794888.1456854014001.JavaMail.yahoo@mail.yahoo.com"
type="cite">
<div style="color:#000; background-color:#fff;
font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica
Neue, Helvetica, Arial, Lucida Grande,
sans-serif;font-size:16px">
<div id="yui_3_16_0_1_1456853527172_2190"><span>Hi all,</span></div>
<div id="yui_3_16_0_1_1456853527172_2190"><span><br>
</span></div>
<div id="yui_3_16_0_1_1456853527172_2190" class=""><span
style="font-family: 'Segoe UI', Helvetica, Arial,
sans-serif; font-size: medium;"
id="yui_3_16_0_1_1456853527172_2738" class="">I want to
introduce a new network entity, Location Server (LS) for
some reason, and have MNs and PITRs interact with it as
follows:</span><br style="font-family: 'Segoe UI',
Helvetica, Arial, sans-serif; font-size: medium;"
id="yui_3_16_0_1_1456853527172_2740" class="">
</div>
<ul style="font-family: 'Segoe UI', Helvetica, Arial,
sans-serif; font-size: medium; margin-top: 14pt;
margin-bottom: 14pt;" id="yui_3_16_0_1_1456853527172_2742"
class="">
<li id="yui_3_16_0_1_1456853527172_2744" class="">When an MN
detects its interface signal dropping (which is going to be
determined by an external program), <i
id="yui_3_16_0_1_1456853527172_2746" class="">MN should
issue Map-Reply(LS) to PITR, and Map-Reply(NULL) to LS</i>.</li>
<li id="yui_3_16_0_1_1456853527172_2748" class="">When an MN's
interface comes back up after binding to a new address RLOC,
and the MN (eventually) issues Map-Reply(RLOC) to PITR, <i
id="yui_3_16_0_1_1456853527172_2750" class="">MN should
also issue Map-Reply(RLOC) to LS</i>.</li>
</ul>
</div>
</blockquote>
Are you trying to modify the SMR process to also send a Map Reply to
the LS with the specified RLOCs of the previous point, or you are
sending directly map replys? <br>
<br>
<blockquote
cite="mid:532046786.1794888.1456854014001.JavaMail.yahoo@mail.yahoo.com"
type="cite">
<div style="color:#000; background-color:#fff;
font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica
Neue, Helvetica, Arial, Lucida Grande,
sans-serif;font-size:16px">
<div style="font-family: 'Segoe UI', Helvetica, Arial,
sans-serif; font-size: medium; margin-top: 14pt;
margin-bottom: 14pt;" id="yui_3_16_0_1_1456853527172_2752"
class="">As we know, a Solicit-Map-Request (SMR) is sent to
PITR at interface up, and the PITR sends a Map-Request to the
MN, which then sends a Map-Reply with its new RLOC.
tr_recv_map_request() in control/lisp_xtr.c appears to handle
the incoming Map-Request and respond with a Map-Reply, so I
intend to modify this function to deal with both interaction,
and supply it through the lisp_xtr_r structure with a flag to
distinguish the two behaviours, and the LS address. The flag
will be set if the signal drop has been detected, and cleared
if the interface has come back up. There are two
modifications:<br>
</div>
<ul style="font-family: 'Segoe UI', Helvetica, Arial,
sans-serif; font-size: medium; margin-top: 14pt;
margin-bottom: 14pt;" id="yui_3_16_0_1_1456853527172_2760"
class="">
<li id="yui_3_16_0_1_1456853527172_2762" class="">If the flag
is set, Map-Reply(LS) will be sent to PITR instead of
Map-Reply(RLOC).</li>
<li id="yui_3_16_0_1_1456853527172_2764" class="">An
additional Map-Reply(flag ? NULL : RLOC) will be sent to LS.</li>
</ul>
</div>
</blockquote>
The SMR process not only affects to the PiTR but also all the
entries of the map cache. <br>
<blockquote
cite="mid:532046786.1794888.1456854014001.JavaMail.yahoo@mail.yahoo.com"
type="cite">
<div style="color:#000; background-color:#fff;
font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica
Neue, Helvetica, Arial, Lucida Grande,
sans-serif;font-size:16px">
<div dir="ltr" id="yui_3_16_0_1_1456853527172_2783"><span
style="font-family: 'Segoe UI', Helvetica, Arial,
sans-serif; font-size: medium;"
id="yui_3_16_0_1_1456853527172_2766" class="">For the first
change, can someone explain how the RLOC currently gets set
in the new message? Is it uc->la, for example? Or do I
need to build a new mapping_t?</span><br style="font-family:
'Segoe UI', Helvetica, Arial, sans-serif; font-size:
medium;" id="yui_3_16_0_1_1456853527172_2768" class="">
</div>
</div>
</blockquote>
uc is just used to indicate the IPs and the udp ports to be used to
send the packet. You will probably have to generate a mapping with
the new RLOCs you want to use<br>
<blockquote
cite="mid:532046786.1794888.1456854014001.JavaMail.yahoo@mail.yahoo.com"
type="cite">
<div style="color:#000; background-color:#fff;
font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica
Neue, Helvetica, Arial, Lucida Grande,
sans-serif;font-size:16px">
<div dir="ltr" id="yui_3_16_0_1_1456853527172_2783"><br
style="font-family: 'Segoe UI', Helvetica, Arial,
sans-serif; font-size: medium;"
id="yui_3_16_0_1_1456853527172_2770" class="">
<span style="font-family: 'Segoe UI', Helvetica, Arial,
sans-serif; font-size: medium;"
id="yui_3_16_0_1_1456853527172_2772" class="">For the second
change, I don't strictly have to use a Map-Reply, as my code
will be talking to my LS, but it would be nice to re-use the
message type. What could I do to express some sort of
Map-Reply(NULL)? Use lisp_msg_put_neg_mapping, perhaps? Or
just an all-zero IP address?</span><br style="font-family:
'Segoe UI', Helvetica, Arial, sans-serif; font-size:
medium;" id="yui_3_16_0_1_1456853527172_2774" class="">
</div>
</div>
</blockquote>
Yes, using a negative map reply (locator_count = 0) will be useful.
Other possibilities could be to use priority 255 in order to
indicate to not use the locators. When you create the mapping you
also add a locator for the LS and then you change priority to 255 of
the locators you don't want to be used.<br>
<blockquote
cite="mid:532046786.1794888.1456854014001.JavaMail.yahoo@mail.yahoo.com"
type="cite">
<div style="color:#000; background-color:#fff;
font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica
Neue, Helvetica, Arial, Lucida Grande,
sans-serif;font-size:16px">
<div dir="ltr" id="yui_3_16_0_1_1456853527172_2783"><br
style="font-family: 'Segoe UI', Helvetica, Arial,
sans-serif; font-size: medium;"
id="yui_3_16_0_1_1456853527172_2776" class="">
<br style="font-family: 'Segoe UI', Helvetica, Arial,
sans-serif; font-size: medium;"
id="yui_3_16_0_1_1456853527172_2780" class="">
<span style="font-family: 'Segoe UI', Helvetica, Arial,
sans-serif; font-size: medium;"
id="yui_3_16_0_1_1456853527172_2782" class="">It looks like
send_all_smr_and_reg() sends SMR, so that will result in a
later invocation of tr_recv_map_request(). It is only
invoked from send_all_smr_cb(), which appears to be invoked
by a timer. Is that timer set as a result of a new binding,
i.e., so that SMR will be sent a short moment after the new
binding is established? IOW, does the invocation of
send_all_smr_cb() imply that the lisp_xtr object has learned
of the new binding? If so, I intend to clear the flag
inside send_all_smr_cb(), so that the subsequent (indirect)
invocation of tr_recv_map_request() will behave normally to
PITR (as well as send an additional message to LS). I will
also add a non-static function to set the flag, and then
call send_all_smr_and_reg(). I will later arrange to call
this new function when the signal drop is detected.</span><span><br>
</span></div>
</div>
</blockquote>
We have a structure for each interface (iface_locators) which
contain the changes produced in the interface. When we receive a
netlink message we update this structure and we program the SMR
timer. If we receive a new netlink message before the timer expires,
we reprogram the timer again. When timer expires we call <span
style="font-family: 'Segoe UI', Helvetica, Arial, sans-serif;
font-size: medium;" id="yui_3_16_0_1_1456853527172_2782" class="">send_all_smr_cb
where</span> we check the iface_locators structures to decide if
we have to do a SMR or if we had a flapping situation and we don't
need to initiate the SMR.<br>
<br>
I hope with this information you can proceed with your development.<br>
<br>
Best regards<br>
<br>
Albert<br>
<blockquote
cite="mid:532046786.1794888.1456854014001.JavaMail.yahoo@mail.yahoo.com"
type="cite">
<div style="color:#000; background-color:#fff;
font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica
Neue, Helvetica, Arial, Lucida Grande,
sans-serif;font-size:16px">
<div dir="ltr" id="yui_3_16_0_1_1456853527172_2783"><span
style="font-family: 'Segoe UI', Helvetica, Arial,
sans-serif; font-size: medium;" class=""><br>
</span></div>
<div dir="ltr" id="yui_3_16_0_1_1456853527172_2783"><span
style="font-family: 'Segoe UI', Helvetica, Arial,
sans-serif; font-size: medium;" class=""
id="yui_3_16_0_1_1456853527172_2967">Regards,</span></div>
<div id="yui_3_16_0_1_1456853527172_2735"> </div>
<div class="signature" id="yui_3_16_0_1_1456853527172_2726">
<div id="yui_3_16_0_1_1456853527172_2725">
<div style="font-family:Tahoma;font-size:13px;"
class="yui_3_2_0_18_1337194888927129"
id="yui_3_16_0_1_1456853527172_2724">
<div style="font-family:arial;font-size:13px;"
id="yui_3_16_0_1_1456853527172_2723">
<div class="MsoNormal"
id="yui_3_16_0_1_1456853527172_2734"><span
style="color:rgb(79, 129, 189);font-family:Euphemia,
sans-serif;font-size:10pt;"
id="yui_3_16_0_1_1456853527172_2733">Musab Isah</span><br>
</div>
<div class="MsoNormal"
id="yui_3_16_0_1_1456853527172_2732"><span
style="font-size:10.0pt;color:#4F81BD;"
id="yui_3_16_0_1_1456853527172_2731">Research
Student,</span></div>
<div class="MsoNormal"
id="yui_3_16_0_1_1456853527172_2730"><span
style="font-size:10.0pt;color:#4F81BD;"
id="yui_3_16_0_1_1456853527172_2729">School of
Computing and Communications,</span></div>
<div class="MsoNormal"
id="yui_3_16_0_1_1456853527172_2728"><span
style="font-size:10.0pt;color:#4F81BD;"
id="yui_3_16_0_1_1456853527172_2727">D29, InfoLab21</span></div>
<div class="MsoNormal"
id="yui_3_16_0_1_1456853527172_2722"><span
style="font-size:10.0pt;color:#4F81BD;"
id="yui_3_16_0_1_1456853527172_2721">Lancaster
University</span></div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
<br>
<br>
</body>
</html>