6 Jun
2013
6 Jun
'13
9:06 a.m.
Module: sip-router
Branch: master
Commit: c8e928a2c78ee963f807791bea5aacdd31e05936
URL:
http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=c8e928a…
Author: Daniel-Constantin Mierla <miconda(a)gmail.com>
Committer: Daniel-Constantin Mierla <miconda(a)gmail.com>
Date: Thu Jun 6 09:05:28 2013 +0200
siputils: added new function is_first_hop()
- detect if it is first hop after original sender
- added section ids for functions, remove a duplicate content for
is_rpid_user_e164()
---
modules/siputils/README | 188 +++++++++++++++---------------
modules/siputils/doc/siputils_admin.xml | 104 +++++++++---------
modules/siputils/sipops.c | 89 +++++++++++++--
modules/siputils/sipops.h | 1 +
modules/siputils/siputils.c | 2 +
5 files changed, 229 insertions(+), 155 deletions(-)
Diff:
http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commitdiff;h=c8e…
8 Jun
8 Jun
8:55 a.m.
daniel,
is_first_hop() readme has this on replies:
For incoming SIP replies, it means that top Record-Route URI is
'myself' and source address is not matching it (to avoid detecting in
case of local loops). Note that it does not detect spirals, which can
have the condition for replies true also in the case of additional SIP
reply receival.
in contact alias tutorial
https://sip-router.org/wiki/tutorials/alias-example?&#in-dialog_requests
i have implemented "is first hop" check by checking that reply does not
have any other r-r headers except the ones added by the proxy itself
when it relayed the request:
in request route i set
$avp("rr_count") = $rr_count;
and in reply route, i test
if ($rr_count == $avp(rr_count) + $rr_top_count) ...
i think that this method also works in case of spirals if i understand
correctly what spirals are.
do you have any comment about possible equivalence or non-equivalence of
the two methods? could i safely use is_first_hop test also for replies
in contact alias tutorial?
-- juha
8:59 a.m.
it came to my mind that if sip ua runs on the same host as sip proxy
(which is very common in test environments at least) then it seem that
is_first_hop does not work for replies.
it may not be a good idea to introduce this function for replies if it
has such a hole.
-- juha
10:16 a.m.
On 6/8/13 8:59 AM, Juha Heinanen wrote:
it came to my mind that if sip ua runs on the same
host as sip proxy
(which is very common in test environments at least) then it seem that
is_first_hop does not work for replies.
it may not be a good idea to introduce this function for replies if it
has such a hole.
The check is on ip, port and protocol, if ua is on same host, it
will
use a different port. It is similar situation with record-routing and UA
on same host. Without port matching of 'myself', then contact of UA
which appears as R-URI in subsequent requests will be detected as myself
and eaten by loose_route() by considering a strict routing case.
For now use the test with rr count, it is good for replies.
Cheers,
Daniel
--
Daniel-Constantin Mierla - http://www.asipto.com
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
Kamailio Advanced Training, San Francisco, USA - June 24-27, 2013
* http://asipto.com/u/katu *
10:48 a.m.
Daniel-Constantin Mierla writes:
The check is on ip, port and protocol, if ua is on
same host, it will
use a different port. It is similar situation with record-routing and UA
on same host. Without port matching of 'myself', then contact of UA
which appears as R-URI in subsequent requests will be detected as myself
and eaten by loose_route() by considering a strict routing case.
For now use the test with rr count, it is good for replies.
thanks for the explanation. i got confused about source address, because
readme does not mention that also port is used for matching.
-- juha
10:11 a.m.
Hello,
On 6/8/13 8:55 AM, Juha Heinanen wrote:
daniel,
is_first_hop() readme has this on replies:
For incoming SIP replies, it means that top Record-Route URI is
'myself' and source address is not matching it (to avoid detecting in
case of local loops). Note that it does not detect spirals, which can
have the condition for replies true also in the case of additional SIP
reply receival.
in contact alias tutorial
https://sip-router.org/wiki/tutorials/alias-example?&#in-dialog_requests
i have implemented "is first hop" check by checking that reply does not
have any other r-r headers except the ones added by the proxy itself
when it relayed the request:
in request route i set
$avp("rr_count") = $rr_count;
and in reply route, i test
if ($rr_count == $avp(rr_count) + $rr_top_count) ...
i think that this method also works in case of spirals if i understand
correctly what spirals are.
do you have any comment about possible equivalence or non-equivalence of
the two methods? could i safely use is_first_hop test also for replies
in contact alias tutorial?
Using your approach is safer and good for spirals as
well, but requires
tm module to keep the avp. I need it for a stateless outbound proxy. I
considered storing the number of r-r as a parameter in the new r-r
header, but could become too big with ftag, nat, etc...
Detecting the spiral would require to iterate through r-r headers in
reply, see if there is another match to 'myself' and if yes, check if
source ip/port/proto matches the previous r-r header. That should make
it complete. Right now I know if there is a spiral inside my network, like:
UA1 ==== K ==== Media Server ==== K ==== UA2
but is easy to check that source ip is media server.
Cheers,
Daniel
--
Daniel-Constantin Mierla
http://www.asipto.com
4194
days inactive
4196
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5 comments
3 participants
participants (3)
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Daniel-Constantin Mierla -
Daniel-Constantin Mierla -
Juha Heinanen