8 Apr
2024
8 Apr
'24
5:12 p.m.
Hi all!
For testing purposes, while I am waiting for the ST/SH REST API to be
available from other teams, I developed a small python REST API that
returns a mockup of a JSON object with some of the required values.
The kamailio script, completely stateless as I do not need to keep track of
the sessions, iterates through one of the JSON branches and adds the
destination URLs to the Contact header and replies a SIP 300 Multiple
Choices.
This works: the UAC does receive the SIP response with the Contacts , but
it also receives a SIP 500 error message right after, and I can't figure
out why. And i bet this is simple to solve....
Any clue? I'm aware I'm not processing ACK messages, but the sl_send_reply
403 should do the trick right? ... at least while testing....
Also, as this is a stateless script, is there another way of using async
http or making http requests to a REST API without having to use TM Module?
Thanks in advance.
The kamailio script is has follows:
#!KAMAILIO
/* add API http timeout */
#!define HTTP_API_TIMEOUT 5000
#!define HTTP_API_ROUTING_ENDPOINT "http://some_python_rest_api/get_route"
### LOG Levels: 3=DBG, 2=INFO, 1=NOTICE, 0=WARN, -1=ERR
debug=4
log_stderror=no
memdbg=5
memlog=5
log_facility=LOG_LOCAL0
log_prefix="{$mt $hdr(CSeq) $ci} "
/* number of SIP routing processes */
children=2
/* set paths to location of modules */
loadmodule "tm.so"
loadmodule "jsonrpcs.so"
loadmodule "kex.so"
loadmodule "corex.so"
loadmodule "sl.so"
loadmodule "db_mysql.so"
loadmodule "rr.so"
loadmodule "pv.so"
loadmodule "maxfwd.so"
loadmodule "ipops.so"
loadmodule "textops.so"
loadmodule "siputils.so"
loadmodule "xlog.so"
loadmodule "sanity.so"
loadmodule "ctl.so"
loadmodule "cfg_rpc.so"
loadmodule "uac.so"
loadmodule "counters.so"
loadmodule "http_async_client.so"
loadmodule "jansson.so"
loadmodule "usrloc.so"
/* listen addresses */
listen=udp:10.20.0.2:5060
listen=udp:10.20.0.2:5062
advertised_address="10.20.0.2";
# ----- http_async_client params -----
modparam("http_async_client", "workers", HTTP_ASYNC_CLIENT_WORKERS)
modparam("http_async_client", "connection_timeout", 2000)
request_route {
#route(HANDLE_DMQ);
route(HANDLE_OPTIONS);
if (is_method("INVITE"))
{
xlog("L_INFO","MAIN - calling TO_CARRIER");
route(TO_CARRIER);
exit;
}
else{
sl_send_reply("401","UNAUTHORIZED");
}
}
route[TO_CARRIER]{
xlog("L_INFO","TO_CARRIER - calling RELAY_API");
route(RELAY_API); #Route relay
xlog("L_INFO","TO_CARRIER - return");
return;
}
# Relay request using the API (response)
route[RELAY_API_RESPONSE] {
xlog("L_INFO","RELAY_API_RESPONSE - got response from REST
API");
if ($http_ok==1 && $http_rs==200)
{
xlog("L_INFO","RELAY_API_RESPONSE - HTTP RESPONSE:
$http_rb\n");
if (jansson_get("json", $http_rb, "$var(json)")) {
xlog("L_INFO","RELAY_API_RESPONSE - JSON =
$var(json)");
$var(count) = 0;
jansson_array_size("routes", $var(json),
"$var(size)");
xlog("L_INFO","RELAY_API_RESPONSE -
jansson_array_size");
while ( $var(count) < $var(size) ){
jansson_get("routes[$var(count)].headers.to.uri", $var(rtjson),
"$var(v)");
xlog("L_INFO","JSON - routes[$var(count)]
- $var(v)");
#$(avp(mycontacts)[$var(count)]) =
$avp(mycontacts) + $var(v) + "\r\n";
$avp(mycontacts) = $avp(mycontacts) +
$var(v) + ";";
*append_to_reply("Contact: <" + $var(v)
+">"+ "\r\n"); /* ----
IS THERE A BETTER ?? ..... */*
$var(count) =
$var(count) + 1;
}
xlog("L_INFO","RELAY_API_RESPONSE - RELAY");
xlog("L_INFO","MAIN - calling REPLY_302");
route(REPLY_302);
return;
}
}
send_reply(500, "API Not Available - http response = $http_rs
$http_ok");
exit;
}
route[RELAY_API] {
xlog("L_INFO","RELAY_API - from_ip $si:$sp from_number $fU
to_number $ru");
$http_req(all) = $null;
$http_req(suspend) = 1;
$http_req(timeout) = HTTP_API_TIMEOUT;
$http_req(method) = "POST";
$http_req(hdr) = "Content-Type: application/json";
jansson_set("string","from_ip",$si,
"$var(http_routing_query)");
jansson_set("string","from_port",$sp,
"$var(http_routing_query)");
jansson_set("string","from_number",$fU,
"$var(http_routing_query)");
jansson_set("string","to_number",$ru ,
"$var(http_routing_query)");
xlog("L_INFO","RELAY_API - API ASYNC ROUTING REQUEST:
$var(http_routing_query)\n");
$http_req(body) = $var(http_routing_query);
t_newtran();
http_async_query(HTTP_API_ROUTING_ENDPOINT, "RELAY_API_RESPONSE");
xlog("L_INFO","RELAY_API - Waiting for Response");
}
route[REPLY_302] {
# Sends a 300 Multiple Choices back to the proxy that requested the
routing lookup
xlog("L_INFO","REPLY_302 - send reply");
sl_send_reply("300", "Multiple Choices");
xlog("L_INFO","REPLY_302 - exit");
exit;
}
route[HANDLE_OPTIONS]{
if(is_method("OPTIONS"))
{
sl_send_reply(200, "OK");
exit;
}
if ($fU=="ping")
{
sl_send_reply("200","OK");
exit;
}
}
SNGrep output:
1 - INVITE from UAC to Kamailio
INVITE sip:918228990@10.20.0.2 SIP/2.0
Via: SIP/2.0/UDP
10.20.0.1:5063;branch=z9hG4bK58aa83f4
Max-Forwards: 70
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To: <sip:918228990@10.20.0.2>
Contact: <sip:anonymous@10.20.0.1:5063>
Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063
CSeq: 102 INVITE
User-Agent: SIPp
Date: Mon, 08 Apr 2024 15:09:51 GMT
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO,
PUBLISH, MESSAGE
Supported: replaces, timer
Content-Type: application/sdp
Content-Length: 270
v=0
o=root 2021555890 2021555890 IN IP4 10.20.0.1
s=SIPp
c=IN IP4 10.20.0.1
t=0 0
m=audio 18422 RTP/AVP 8 0 101
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16
a=ptime:20
a=maxptime:150
a=sendrecv
2 - Reply from Kamailio to UAC
SIP/2.0 100 trying -- your call is important to us
Via: SIP/2.0/UDP
10.20.0.1:5063;branch=z9hG4bK58aa83f4
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To: <sip:918228990@10.20.0.2>
Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063
CSeq: 102 INVITE
Server: kamailio (5.7.4 (x86_64/linux))
Content-Length: 0
3 - SIP 300 Multiple Choices from Kamailio to UAC
SIP/2.0 300 Multiple Choices
Via: SIP/2.0/UDP
10.20.0.1:5063;branch=z9hG4bK58aa83f4
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To: <sip:918228990@10.20.0.2
4 - SIP 500 from Kamailio to UAC
SIP/2.0 500 I'm terribly sorry, server error occurred (1/TM)
;tag=57c593265e21c2b70aea50cb414df9cd.32679ccd
Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063
CSeq: 102 INVITE
Contact: <sip:sip:918228990@10.20.0.2@sip.domain.io>
Contact: <sip:+351sip:918228990@10.20.0.2@10.20.0.3>
Server: kamailio (5.7.4 (x86_64/linux))
Content-Length: 0 Via: SIP/2.0/UDP
10.20.0.1:5063;branch=z9hG4bK58aa83f4
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To: <sip:918228990@10.20.0.2
5 - ACK from UAC to Kamailio
ACK sip:918228990@10.20.0.2 SIP/2.0
;tag=4eb2322b7d2b68e6fc3168f503344c21-32679ccd
Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063
CSeq: 102 INVITE
Server: kamailio (5.7.4 (x86_64/linux))
Content-Length: 0 Via: SIP/2.0/UDP
10.20.0.1:5063;branch=z9hG4bK58aa83f4
Max-Forwards: 70
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To: <sip:918228990@10.20.0.2
and continues with ACK and repeating SIP 500 above....
*Sérgio Charrua*
.
;tag=57c593265e21c2b70aea50cb414df9cd.32679ccd
Contact: <sip:anonymous@10.20.0.1:5063>
Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063
CSeq: 102 ACK
User-Agent: SIPp
Content-Length: 0 
8 Apr
8 Apr
5:45 p.m.
On Apr 8, 2024, at 11:12 AM, Sergio Charrua via
sr-users <sr-users(a)lists.kamailio.org> wrote:
Also, as this is a stateless script, is there another way of using async http or making
http requests to a REST API without having to use TM Module?
You can always use an outside service, which communicates with Kamailio asynchronously via
a variety of channels. See the various message brokers, EVAPI, etc.
--
Alex Balashov
Principal Consultant
Evariste Systems LLC
Web: https://evaristesys.com
Tel: +1-706-510-6800
6:33 p.m.
@Alex Balashov <abalashov(a)evaristesys.com>
I thought about EVAPI but I'm afraid it will bring a lot of unnecessary CPU
overload, and in my case I need to have maximum CPS on this server (used
for as STIR/SHAKEN with a REST API...)-
Will have a try with EVAPI.
*Sérgio Charrua*
On Mon, Apr 8, 2024 at 6:14 PM Alex Balashov via sr-users <
sr-users(a)lists.kamailio.org> wrote:
On Apr 8, 2024, at 11:12 AM, Sergio Charrua via
sr-users <
sr-users(a)lists.kamailio.org> wrote:
Also, as this is a stateless script, is there another way of using async
http or
making http requests to a REST API without having to use TM Module?
You can always use an outside service, which communicates with Kamailio
asynchronously via a variety of channels. See the various message brokers,
EVAPI, etc.
--
Alex Balashov
Principal Consultant
Evariste Systems LLC
Web: https://evaristesys.com
Tel: +1-706-510-6800
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To unsubscribe send an email to sr-users-leave(a)lists.kamailio.org
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6 p.m.
The kamailio script, completely stateless as I do not
need to keep track of the sessions, iterates through one of the JSON branches and adds the
destination URLs to the Contact header and replies a SIP 300 Multiple Choices.
The term 'stateless' in the scope of a SIP proxy doesn't mean to keep track of
the session (or the dialog). It means tracking the state of the transaction. In order to
pause the current transaction and resume it (using http_async_query()), a stateful
transaction must be created within Kamailio - and you've done this when you call
`t_newtran()`. As a recommendation, rather than using `sl_send_reply()`, `t_reply()`, or
`t_send_reply()`, just use `send_reply()`, which will send the reply statelessly if
there's no transaction, and statefully if there is a transaction.
If you want to make your replies LOOK stateless to request source, disable automatic 100
Trying from the TM module.
Kaufman
Senior Voice Engineer
E: bkaufman(a)bcmone.com
SIP.US Client Support: 800.566.9810 | SIPTRUNK Client Support: 800.250.6510 |
Flowroute Client Support: 855.356.9768
[img]<https://www.sip.us/>
[img]<https://www.siptrunk.com/>
[img]<https://www.flowroute.com/>
From: Sergio Charrua via sr-users <sr-users(a)lists.kamailio.org>
Sent: Monday, April 8, 2024 10:13 AM
To: Kamailio (SER) - Users Mailing List <sr-users(a)lists.kamailio.org>
Cc: Sergio Charrua <sergio.charrua(a)voip.pt>
Subject: [SR-Users] making HTTP requests in stateless redirects
CAUTION: This email originated from outside the organization. Do not click links or open
attachments unless you recognize the sender and know the content is safe.
Hi all!
For testing purposes, while I am waiting for the ST/SH REST API to be available from other
teams, I developed a small python REST API that returns a mockup of a JSON object with
some of the required values.
The kamailio script, completely stateless as I do not need to keep track of the sessions,
iterates through one of the JSON branches and adds the destination URLs to the Contact
header and replies a SIP 300 Multiple Choices.
This works: the UAC does receive the SIP response with the Contacts , but it also receives
a SIP 500 error message right after, and I can't figure out why. And i bet this is
simple to solve....
Any clue? I'm aware I'm not processing ACK messages, but the sl_send_reply 403
should do the trick right? ... at least while testing....
Also, as this is a stateless script, is there another way of using async http or making
http requests to a REST API without having to use TM Module?
Thanks in advance.
The kamailio script is has follows:
#!KAMAILIO
/* add API http timeout */
#!define HTTP_API_TIMEOUT 5000
#!define HTTP_API_ROUTING_ENDPOINT "http://some_python_rest_api/get_route"
### LOG Levels: 3=DBG, 2=INFO, 1=NOTICE, 0=WARN, -1=ERR
debug=4
log_stderror=no
memdbg=5
memlog=5
log_facility=LOG_LOCAL0
log_prefix="{$mt $hdr(CSeq) $ci} "
/* number of SIP routing processes */
children=2
/* set paths to location of modules */
loadmodule "tm.so"
loadmodule "jsonrpcs.so"
loadmodule "kex.so"
loadmodule "corex.so"
loadmodule "sl.so"
loadmodule "db_mysql.so"
loadmodule "rr.so"
loadmodule "pv.so"
loadmodule "maxfwd.so"
loadmodule "ipops.so"
loadmodule "textops.so"
loadmodule "siputils.so"
loadmodule "xlog.so"
loadmodule "sanity.so"
loadmodule "ctl.so"
loadmodule "cfg_rpc.so"
loadmodule "uac.so"
loadmodule "counters.so"
loadmodule "http_async_client.so"
loadmodule "jansson.so"
loadmodule "usrloc.so"
/* listen addresses */
listen=udp:10.20.0.2:5060
<http://10.20.0.2:5060/>listen=udp:10.20.0.2:5062
<http://10.20.0.2:5062/>advertised_address="10.20.0.2";
# ----- http_async_client params -----
modparam("http_async_client", "workers", HTTP_ASYNC_CLIENT_WORKERS)
modparam("http_async_client", "connection_timeout", 2000)
request_route {
#route(HANDLE_DMQ);
route(HANDLE_OPTIONS);
if (is_method("INVITE"))
{
xlog("L_INFO","MAIN - calling TO_CARRIER");
route(TO_CARRIER);
exit;
}
else{
sl_send_reply("401","UNAUTHORIZED");
}
}
route[TO_CARRIER]{
xlog("L_INFO","TO_CARRIER - calling RELAY_API");
route(RELAY_API); #Route relay
xlog("L_INFO","TO_CARRIER - return");
return;
}
# Relay request using the API (response)
route[RELAY_API_RESPONSE] {
xlog("L_INFO","RELAY_API_RESPONSE - got response from REST API");
if ($http_ok==1 && $http_rs==200)
{
xlog("L_INFO","RELAY_API_RESPONSE - HTTP RESPONSE:
$http_rb\n");
if (jansson_get("json", $http_rb, "$var(json)")) {
xlog("L_INFO","RELAY_API_RESPONSE - JSON =
$var(json)");
$var(count) = 0;
jansson_array_size("routes", $var(json),
"$var(size)");
xlog("L_INFO","RELAY_API_RESPONSE -
jansson_array_size");
while ( $var(count) < $var(size) ){
jansson_get("routes[$var(count)].headers.to.uri", $var(rtjson),
"$var(v)");
xlog("L_INFO","JSON - routes[$var(count)] -
$var(v)");
#$(avp(mycontacts)[$var(count)]) = $avp(mycontacts) +
$var(v) + "\r\n";
$avp(mycontacts) = $avp(mycontacts) + $var(v) +
";";
append_to_reply("Contact: <" + $var(v)
+">"+ "\r\n"); /* ---- IS THERE A BETTER ?? ..... */
$var(count) = $var(count) + 1;
}
xlog("L_INFO","RELAY_API_RESPONSE - RELAY");
xlog("L_INFO","MAIN - calling REPLY_302");
route(REPLY_302);
return;
}
}
send_reply(500, "API Not Available - http response = $http_rs
$http_ok");
exit;
}
route[RELAY_API] {
xlog("L_INFO","RELAY_API - from_ip $si:$sp from_number $fU
to_number $ru");
$http_req(all) = $null;
$http_req(suspend) = 1;
$http_req(timeout) = HTTP_API_TIMEOUT;
$http_req(method) = "POST";
$http_req(hdr) = "Content-Type: application/json";
jansson_set("string","from_ip",$si,
"$var(http_routing_query)");
jansson_set("string","from_port",$sp,
"$var(http_routing_query)");
jansson_set("string","from_number",$fU,
"$var(http_routing_query)");
jansson_set("string","to_number",$ru ,
"$var(http_routing_query)");
xlog("L_INFO","RELAY_API - API ASYNC ROUTING REQUEST:
$var(http_routing_query)\n");
$http_req(body) = $var(http_routing_query);
t_newtran();
http_async_query(HTTP_API_ROUTING_ENDPOINT, "RELAY_API_RESPONSE");
xlog("L_INFO","RELAY_API - Waiting for Response");
}
route[REPLY_302] {
# Sends a 300 Multiple Choices back to the proxy that requested the routing lookup
xlog("L_INFO","REPLY_302 - send reply");
sl_send_reply("300", "Multiple Choices");
xlog("L_INFO","REPLY_302 - exit");
exit;
}
route[HANDLE_OPTIONS]{
if(is_method("OPTIONS"))
{
sl_send_reply(200, "OK");
exit;
}
if ($fU=="ping")
{
sl_send_reply("200","OK");
exit;
}
}
SNGrep output:
1 - INVITE from UAC to Kamailio
INVITE sip:918228990@10.20.0.2<mailto:sip%3A918228990@10.20.0.2> SIP/2.0
Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4
Max-Forwards: 70
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To: <sip:918228990@10.20.0.2<mailto:sip%3A918228990@10.20.0.2>>
Contact: <sip:anonymous@10.20.0.1:5063<http://sip:anonymous@10.20.0.1:5063/>>
Call-ID:
531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063<http://531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063/>
CSeq: 102 INVITE
User-Agent: SIPp
Date: Mon, 08 Apr 2024 15:09:51 GMT
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH,
MESSAGE
Supported: replaces, timer
Content-Type: application/sdp
Content-Length: 270
v=0
o=root 2021555890 2021555890 IN IP4 10.20.0.1
s=SIPp
c=IN IP4 10.20.0.1
t=0 0
m=audio 18422 RTP/AVP 8 0 101
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16
a=ptime:20
a=maxptime:150
a=sendrecv
2 - Reply from Kamailio to UAC
SIP/2.0 100 trying -- your call is important to us
Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To: <sip:918228990@10.20.0.2<mailto:sip%3A918228990@10.20.0.2>>
Call-ID:
531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063<http://531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063/>
CSeq: 102 INVITE
Server: kamailio (5.7.4 (x86_64/linux))
Content-Length: 0
3 - SIP 300 Multiple Choices from Kamailio to UAC
SIP/2.0 300 Multiple Choices
Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To:
<sip:918228990@10.20.0.2<mailto:sip%3A918228990@10.20.0.2>>;tag=57c593265e21c2b70aea50cb414df9cd.32679ccd
Call-ID:
531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063<http://531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063/>
CSeq: 102 INVITE
Contact: <sip:sip:918228990@10.20.0.2@sip.domain.io<http://sip.domain.io/>>
Contact: <sip:+351sip:918228990@10.20.0.2@10.20.0.3<http://10.20.0.3/>>
Server: kamailio (5.7.4 (x86_64/linux))
Content-Length: 0
4 - SIP 500 from Kamailio to UAC
SIP/2.0 500 I'm terribly sorry, server error occurred (1/TM)
Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To:
<sip:918228990@10.20.0.2<mailto:sip%3A918228990@10.20.0.2>>;tag=4eb2322b7d2b68e6fc3168f503344c21-32679ccd
Call-ID:
531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063<http://531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063/>
CSeq: 102 INVITE
Server: kamailio (5.7.4 (x86_64/linux))
Content-Length: 0
5 - ACK from UAC to Kamailio
ACK sip:918228990@10.20.0.2<mailto:sip%3A918228990@10.20.0.2> SIP/2.0
Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4
Max-Forwards: 70
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To:
<sip:918228990@10.20.0.2<mailto:sip%3A918228990@10.20.0.2>>;tag=57c593265e21c2b70aea50cb414df9cd.32679ccd
Contact: <sip:anonymous@10.20.0.1:5063<http://sip:anonymous@10.20.0.1:5063/>>
Call-ID:
531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063<http://531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063/>
CSeq: 102 ACK
User-Agent: SIPp
Content-Length: 0
and continues with ACK and repeating SIP 500 above....
Sérgio Charrua
.
6:28 p.m.
@Ben Kaufman : thanks, I will try that!
@Nick Digalaks : isn't that necessary to have a correct http async
transaction? the async_http module does make/need the TM module to be
loaded....and all examples I got for the async_http module had t_newtran()
method added prior to executing http request....
*Sérgio Charrua*
On Mon, Apr 8, 2024 at 6:20 PM Nick Digalakis <ntg_13(a)hotmail.com> wrote:
I didn't test this, but why are you calling
t_newtran(); if you only want
to send the 300 response?
On Apr 8, 2024 18:12, Sergio Charrua via sr-users <
sr-users(a)lists.kamailio.org> wrote:
Hi all!
For testing purposes, while I am waiting for the ST/SH REST API to be
available from other teams, I developed a small python REST API that
returns a mockup of a JSON object with some of the required values.
The kamailio script, completely stateless as I do not need to keep track
of the sessions, iterates through one of the JSON branches and adds the
destination URLs to the Contact header and replies a SIP 300 Multiple
Choices.
This works: the UAC does receive the SIP response with the Contacts , but
it also receives a SIP 500 error message right after, and I can't figure
out why. And i bet this is simple to solve....
Any clue? I'm aware I'm not processing ACK messages, but the sl_send_reply
403 should do the trick right? ... at least while testing....
Also, as this is a stateless script, is there another way of using async
http or making http requests to a REST API without having to use TM Module?
Thanks in advance.
The kamailio script is has follows:
#!KAMAILIO
/* add API http timeout */
#!define HTTP_API_TIMEOUT 5000
#!define HTTP_API_ROUTING_ENDPOINT "http://some_python_rest_api/get_route"
### LOG Levels: 3=DBG, 2=INFO, 1=NOTICE, 0=WARN, -1=ERR
debug=4
log_stderror=no
memdbg=5
memlog=5
log_facility=LOG_LOCAL0
log_prefix="{$mt $hdr(CSeq) $ci} "
/* number of SIP routing processes */
children=2
/* set paths to location of modules */
loadmodule "tm.so"
loadmodule "jsonrpcs.so"
loadmodule "kex.so"
loadmodule "corex.so"
loadmodule "sl.so"
loadmodule "db_mysql.so"
loadmodule "rr.so"
loadmodule "pv.so"
loadmodule "maxfwd.so"
loadmodule "ipops.so"
loadmodule "textops.so"
loadmodule "siputils.so"
loadmodule "xlog.so"
loadmodule "sanity.so"
loadmodule "ctl.so"
loadmodule "cfg_rpc.so"
loadmodule "uac.so"
loadmodule "counters.so"
loadmodule "http_async_client.so"
loadmodule "jansson.so"
loadmodule "usrloc.so"
/* listen addresses */
listen=udp:10.20.0.2:5060
listen=udp:10.20.0.2:5062
advertised_address="10.20.0.2";
# ----- http_async_client params -----
modparam("http_async_client", "workers", HTTP_ASYNC_CLIENT_WORKERS)
modparam("http_async_client", "connection_timeout", 2000)
request_route {
#route(HANDLE_DMQ);
route(HANDLE_OPTIONS);
if (is_method("INVITE"))
{
xlog("L_INFO","MAIN - calling TO_CARRIER");
route(TO_CARRIER);
exit;
}
else{
sl_send_reply("401","UNAUTHORIZED");
}
}
route[TO_CARRIER]{
xlog("L_INFO","TO_CARRIER - calling RELAY_API");
route(RELAY_API); #Route relay
xlog("L_INFO","TO_CARRIER - return");
return;
}
# Relay request using the API (response)
route[RELAY_API_RESPONSE] {
xlog("L_INFO","RELAY_API_RESPONSE - got response from REST
API");
if ($http_ok==1 && $http_rs==200)
{
xlog("L_INFO","RELAY_API_RESPONSE - HTTP RESPONSE:
$http_rb\n");
if (jansson_get("json", $http_rb, "$var(json)")) {
xlog("L_INFO","RELAY_API_RESPONSE - JSON =
$var(json)");
$var(count) = 0;
jansson_array_size("routes", $var(json),
"$var(size)");
xlog("L_INFO","RELAY_API_RESPONSE -
jansson_array_size");
while ( $var(count) < $var(size) ){
jansson_get("routes[$var(count)].headers.to.uri", $var(rtjson),
"$var(v)");
xlog("L_INFO","JSON - routes[$var(count)]
- $var(v)");
#$(avp(mycontacts)[$var(count)]) =
$avp(mycontacts) + $var(v) + "\r\n";
$avp(mycontacts) = $avp(mycontacts) +
$var(v) + ";";
*append_to_reply("Contact: <" + $var(v)
+">"+ "\r\n"); /* ---- IS THERE A BETTER ?? ..... */*
$var(count) = $var(count) + 1;
}
xlog("L_INFO","RELAY_API_RESPONSE - RELAY");
xlog("L_INFO","MAIN - calling REPLY_302");
route(REPLY_302);
return;
}
}
send_reply(500, "API Not Available - http response = $http_rs
$http_ok");
exit;
}
route[RELAY_API] {
xlog("L_INFO","RELAY_API - from_ip $si:$sp from_number $fU
to_number $ru");
$http_req(all) = $null;
$http_req(suspend) = 1;
$http_req(timeout) = HTTP_API_TIMEOUT;
$http_req(method) = "POST";
$http_req(hdr) = "Content-Type: application/json";
jansson_set("string","from_ip",$si,
"$var(http_routing_query)");
jansson_set("string","from_port",$sp,
"$var(http_routing_query)");
jansson_set("string","from_number",$fU,
"$var(http_routing_query)");
jansson_set("string","to_number",$ru ,
"$var(http_routing_query)");
xlog("L_INFO","RELAY_API - API ASYNC ROUTING REQUEST:
$var(http_routing_query)\n");
$http_req(body) = $var(http_routing_query);
t_newtran();
http_async_query(HTTP_API_ROUTING_ENDPOINT, "RELAY_API_RESPONSE");
xlog("L_INFO","RELAY_API - Waiting for Response");
}
route[REPLY_302] {
# Sends a 300 Multiple Choices back to the proxy that requested the
routing lookup
xlog("L_INFO","REPLY_302 - send reply");
sl_send_reply("300", "Multiple Choices");
xlog("L_INFO","REPLY_302 - exit");
exit;
}
route[HANDLE_OPTIONS]{
if(is_method("OPTIONS"))
{
sl_send_reply(200, "OK");
exit;
}
if ($fU=="ping")
{
sl_send_reply("200","OK");
exit;
}
}
SNGrep output:
1 - INVITE from UAC to Kamailio
INVITE sip:918228990@10.20.0.2 SIP/2.0
Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4
Max-Forwards: 70
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To: <sip:918228990@10.20.0.2>
Contact: <sip:anonymous@10.20.0.1:5063>
Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063
CSeq: 102 INVITE
User-Agent: SIPp
Date: Mon, 08 Apr 2024 15:09:51 GMT
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO,
PUBLISH, MESSAGE
Supported: replaces, timer
Content-Type: application/sdp
Content-Length: 270
v=0
o=root 2021555890 2021555890 IN IP4 10.20.0.1
s=SIPp
c=IN IP4 10.20.0.1
t=0 0
m=audio 18422 RTP/AVP 8 0 101
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16
a=ptime:20
a=maxptime:150
a=sendrecv
2 - Reply from Kamailio to UAC
SIP/2.0 100 trying -- your call is important to us
Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To: <sip:918228990@10.20.0.2>
Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063
CSeq: 102 INVITE
Server: kamailio (5.7.4 (x86_64/linux))
Content-Length: 0
3 - SIP 300 Multiple Choices from Kamailio to UAC
SIP/2.0 300 Multiple Choices
Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To: <sip:918228990@10.20.0.2
;tag=57c593265e21c2b70aea50cb414df9cd.32679ccd
Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063
CSeq: 102 INVITE
Contact: <sip:sip:918228990@10.20.0.2@sip.domain.io>
Contact: <sip:+351sip:918228990@10.20.0.2@10.20.0.3>
Server: kamailio (5.7.4 (x86_64/linux))
Content-Length: 0
4 - SIP 500 from Kamailio to UAC
SIP/2.0 500 I'm terribly sorry, server error occurred (1/TM)
Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To: <sip:918228990@10.20.0.2
;tag=4eb2322b7d2b68e6fc3168f503344c21-32679ccd
Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063
CSeq: 102 INVITE
Server: kamailio (5.7.4 (x86_64/linux))
Content-Length: 0
5 - ACK from UAC to Kamailio
ACK sip:918228990@10.20.0.2 SIP/2.0
Via: SIP/2.0/UDP 10.20.0.1:5063;branch=z9hG4bK58aa83f4
Max-Forwards: 70
From: "Anonymous" <sip:anonymous@anonymous.invalid:5063>;tag=as192b8891
To: <sip:918228990@10.20.0.2
;tag=57c593265e21c2b70aea50cb414df9cd.32679ccd
Contact: <sip:anonymous@10.20.0.1:5063>
Call-ID: 531668b959674f9f667f1c923d1d6c94@10.20.0.1:5063
CSeq: 102 ACK
User-Agent: SIPp
Content-Length: 0
and continues with ACK and repeating SIP 500 above....
*Sérgio Charrua*
.
27
days inactive
27
days old
6 comments
4 participants
participants (4)
-
Alex Balashov -
Ben Kaufman -
Nick Digalakis -
Sergio Charrua