kamailio/modules/xcap_server

XCAP Server Module

Daniel-Constantin Mierla



Edited by

Daniel-Constantin Mierla



Copyright � 2010 asipto.com
__________________________________________________________________

Table of Contents

1. Admin Guide

1. Overview
2. Dependencies

2.1. Kamailio Modules
2.2. External Libraries or Applications

3. Parameters

3.1. db_url (string)
3.2. xcap_table (string)
3.3. xcap_root (str)
3.4. buf_size (int)
3.5. xml_ns (str)
3.6. directory_scheme (int)
3.7. directory_hostname (str)

4. Functions

4.1. xcaps_put(uri, path, doc)
4.2. xcaps_get(uri, path)
4.3. xcaps_del(uri, path)

5. Exported pseudo-variables
6. Simple XCAP Server Config

List of Examples

1.1. Set the "db_url" parameter
1.2. Set the "xcap_table" parameter
1.3. Set url_match parameter
1.4. Set the "buf_size" parameter
1.5. Set xml_ns parameter
1.6. Set directory_scheme parameter
1.7. Set directory_hostname parameter
1.8. xcaps_put usage
1.9. xcaps_get usage
1.10. xcaps_del usage
1.11. $xcapuri(...) PV
1.12. sample xcap server

Chapter 1. Admin Guide

Table of Contents

1. Overview
2. Dependencies

2.1. Kamailio Modules
2.2. External Libraries or Applications

3. Parameters

3.1. db_url (string)
3.2. xcap_table (string)
3.3. xcap_root (str)
3.4. buf_size (int)
3.5. xml_ns (str)
3.6. directory_scheme (int)
3.7. directory_hostname (str)

4. Functions

4.1. xcaps_put(uri, path, doc)
4.2. xcaps_get(uri, path)
4.3. xcaps_del(uri, path)

5. Exported pseudo-variables
6. Simple XCAP Server Config

1. Overview

This module provides an XCAP server functionaly inside Kamailio and SER
SIP servers.

Benefits brought by this integrated XCAP server:
* reuse of SIP router transport layer - XCAP documents can be sent
via SIP (UDP, TCP, TLS and SCTP) and via HTTP (TCP or TLS (HTTPS)).
For HTTP/S, you neet to load XHTTP module to handle HTTP/S
requests.
* the Presence server has access imediatelly to the latest version of
XCAP documents. No more need to trigger refresh of XCAP documents
via MI command
* can be used stand-alone, with a different Presence server. It is
not specific for Kamailio or SER. Documents can be fetched via GET
* no exotic dependencies, it is written in C. It depends on libxml2,
sl module and a database module (required to store the xcap
documents).
* you can do digest authentication using database, radius, ldap, etc.
Can reuse authorization mechanisms provided by SIP server.
* flexibility - the XCAP server is controlled from config file of SIP
server, therefore you can blend the XCAP logic with features
provided by core or other modules.

Important: be sure you have global parameter: 'tcp_accept_no_cl=yes'.

2. Dependencies

2.1. Kamailio Modules
2.2. External Libraries or Applications

2.1. Kamailio Modules

The following modules must be loaded before this module:
* sl - stateless reply module
* db - a database engine module
* xhttp - embedded HTTP server if you want to get XCAP documents via
HTTP.

2.2. External Libraries or Applications

The following libraries or applications must be installed before
running Kamailio with this module loaded:
* libxml2 - libxml2 library for runtime and libxml2-dev for
compilation.

3. Parameters

3.1. db_url (string)
3.2. xcap_table (string)
3.3. xcap_root (str)
3.4. buf_size (int)
3.5. xml_ns (str)
3.6. directory_scheme (int)
3.7. directory_hostname (str)

3.1. db_url (string)

Database URL.

Default value is "mysql://kamailio:kamailiorw@localhost/kamailio".

Example 1.1. Set the "db_url" parameter
...
modparam("xcap_server", "db_url", "mysql://user:[email protected]/dbname")
...

3.2. xcap_table (string)

The name of table where to store the xcap documents.

Default value is "xcap".

Example 1.2. Set the "xcap_table" parameter
...
modparam("xcap_server", "xcap_table", "xcapdocs")
...

3.3. xcap_root (str)

XCAP root URL.

Default value is '/xcap-root/'.

Example 1.3. Set url_match parameter
...
modparam("xcap_server", "xcap_root", "/xcap-root/")
...

3.4. buf_size (int)

Size of local buffer for handling XCAP documents.

Default value is "1024".

Example 1.4. Set the "buf_size" parameter
...
modparam("xcap_server", "buf_size", 2048)
...

3.5. xml_ns (str)

Register extra XML namespaces to be used with XPath. You can set the
parameter many times to add more namespaces. The format is
'prefix=href'.

Default value is 'null'.

Example 1.5. Set xml_ns parameter
...
modparam("xcap_server", "xml_ns",
"rl=urn:ietf:params:xml:ns:resource-lists")
modparam("xcap_server", "xml_ns",
"my=urn:my:prefix")
...

3.6. directory_scheme (int)

Allows the scheme used in org.openmobilealliance.xcap-directory
listings to be set to a specific value.

The URLs in an org.oma.xcap-directory listing must be be paths a client
can use to download the listed XCAP documents. In some cases (for
example, when the XCAP server is accessed using HTTP from an HTTP proxy
the client connectes to using HTTPS) the XCAP server may not be able to
automatically determine the correct scheme to use based on the HTTP
connection.
* -1 (default) - determine scheme automatically. HTTP for TCP
connections and HTTPS for TLS connections.
* 0 - use the HTTP scheme.
* 1 - use the HTTPS scheme.

Example 1.6. Set directory_scheme parameter
...
modparam("xcap_server", "directory_scheme", 0)
...

3.7. directory_hostname (str)

Allows the hostname (and port) used in
org.openmobilealliance.xcap-directory listings to be set to a specific
value.

The URLs in an org.oma.xcap-directory listing must be be paths a client
can use to download the listed XCAP documents. In some cases (for
example, when the XCAP server is accessed through a proxy that
re-writes headers, or a client is non-conformant and does not include a
Host: header) the XCAP server may not be able to automatically
determine the correct hostname to use.

When this parameter is not set the XCAP server will attempt to use the
contents of the (mandatory) Host: header. If the Host: header is not
present the XCAP server will use the IP address and port the XCAP
request was received on.

Example 1.7. Set directory_hostname parameter
...
modparam("xcap_server", "directory_hostname", "xcap.example.com")
...

4. Functions

4.1. xcaps_put(uri, path, doc)
4.2. xcaps_get(uri, path)
4.3. xcaps_del(uri, path)

4.1. xcaps_put(uri, path, doc)

Handle XCAP PUT command.

Example 1.8. xcaps_put usage
...
event_route[xhttp:request] {
if($hu=~"^/xcap-root/")
{
# xcap ops
switch($rm) {
case "PUT":
xcaps_put("sip:101@$Ri", "$hu", "$rb");
exit;
break;
}
}
}
...

4.2. xcaps_get(uri, path)

Handle XCAP GET command.

Example 1.9. xcaps_get usage
...
event_route[xhttp:request] {
if($hu=~"^/xcap-root/")
{
# xcap ops
switch($rm) {
case "GETT":
xcaps_get("sip:101@$Ri", "$hu");
exit;
break;
}
}
}
...

4.3. xcaps_del(uri, path)

Handle XCAP DELETE command.

Example 1.10. xcaps_del usage
...
event_route[xhttp:request] {
if($hu=~"^/xcap-root/")
{
# xcap ops
switch($rm) {
case "DELETE":
xcaps_del("sip:101@$Ri", "$hu");
exit;
break;
}
}
}
...

5. Exported pseudo-variables

* $xcapuri(name=>key) - name can be any to idenitfy the XCAP uri; key
can be: data, uri, root, auid, type, tree, xuid, file, node,
target, domain, uri_adoc.

Exported pseudo-variables are documented at
http://www.kamailio.org/wiki/.

Example 1.11. $xcapuri(...) PV
...
$xcapuri(u=>data) = $hu;
xdbg("SCRIPT: xcap service $xcapuri(u=>auid) for $xcapuri(u=>xuid)\n");
...

6. Simple XCAP Server Config

Example 1.12. sample xcap server
...
tcp_accept_no_cl=yes
...
loadmodule "xhttp.so"
loadmodule "xcap_server.so"

...

# ----- xcap_server params -----
modparam("xcap_server", "db_url",
"mysql://kamailio:kamailiorw@localhost/kamailio")

...

event_route[xhttp:request] {
if (!www_authorize("xcap", "subscriber"))
{
www_challenge("xcap", "0");
exit;
}
if($hu=~"^/xcap-root/")
{
set_reply_close();
set_reply_no_connect();
# xcap ops - break down http uri to get xcap user id
$xcapuri(u=>data) = $hu;
if($xcapuri(u=>xuid)=~"^sip:.+@.+")
$var(uri) = $xcapuri(u=>xuid);
else
$var(uri) = "sip:"+ $xcapuri(u=>xuid) + "@" + $Ri;

# handle XCAP capability request
if($xcapuri(u=>auid)=="xcap-caps")
{
if ($rm == "GET")
{
$var(xbody) =
"


rls-services
pidf-manipulation
xcap-caps
resource-lists
pres-rules
org.openmobilealliance.pres-rules
org.openmobilealliance.user-profile
org.openmobilealliance.pres-content
org.openmobilealliance.search
org.openmobilealliance.xcap-directory




urn:ietf:params:xml:ns:rls-services
urn:ietf:params:xml:ns:pidf
urn:ietf:params:xml:ns:xcap-caps
urn:ietf:params:xml:ns:resource-lists
urn:ietf:params:xml:ns:pres-rules
urn:oma:xml:xdm:user-profile
urn:oma:xml:prs:pres-content
urn:oma:xml:xdm:search
urn:oma:xml:xdm:xcap-directory

";
xhttp_reply("200", "ok", "application/xcap-caps+xml",
"$var(xbody)");
}
else
{
append_to_reply("Allow: GET\r\n");
xhttp_reply("405", "Method Not Allowed", "", "");
}
exit;
}
# be sure auth user access only its documents
if ($au!=$(var(uri){uri.user})) {
xhttp_reply("403", "Forbidden", "text/html",
"operation not allowed");
exit;
}

xdbg("SCRIPT: xcap service $xcapuri(u=>auid) for $xcapuri(u=>xuid)\n");
switch($rm) {
case "PUT":
xcaps_put("$var(uri)", "$hu", "$rb");
if($xcapuri(u=>auid)=~"pres-rules")
{
pres_update_watchers("$var(uri)", "presence");
pres_refresh_watchers("$var(uri)", "presence", 1);
}
else if($xcapuri(u=>auid)=~"rls-services"
|| $xcapuri(u=>auid)=~"resource-lists")
{
rls_update_subs("$var(uri)", "presence");
}
else if($xcapuri(u=>auid)=~"pidf-manipulation")
{
pres_refresh_watchers("$var(uri)", "presence", 2,
"$xcapuri(u=>uri_adoc)",
"$xcapuri(u=>file)");
}
exit;
break;
case "GET":
xcaps_get("$var(uri)", "$hu");
exit;
break;
case "DELETE":
xcaps_del("$var(uri)", "$hu");
if($xcapuri(u=>auid)=~"pres-rules")
{
pres_update_watchers("$var(uri)", "presence");
pres_refresh_watchers("$var(uri)", "presence", 1);
}
else if($xcapuri(u=>auid)=~"rls-services"
|| $xcapuri(u=>auid)=~"resource-lists")
{
rls_update_subs("$var(uri)", "presence");
}
else if($xcapuri(u=>auid)=~"pidf-manipulation")
{
pres_refresh_watchers("$var(uri)", "presence", 2,
"$xcapuri(u=>uri_adoc)",
"$xcapuri(u=>file)");
}
exit;
break;
case "POST":
if($xcapuri(u=>auid)=~"search")
{
xhttp_reply("501", "Not Implemented", "", "");
}
else
{
if($xcapuri(u=>auid)=~"xcap-directory")
{
append_to_reply("Allow: GET\r\n");
}
else
{
append_to_reply("Allow: DELETE, GET, PUT\r\n");
}
xhttp_reply("405", "Method Not Allowed", "", "");
}
exit;
break;
}
}

# other http requests
xhttp_reply("404", "Not Found", "", "");
exit;
}
...

The URL for XCAP has to be:

http://_your_sip_server_ip_:_your_sip_server_port_/xcap-root/...

For example, if your SIP server IP is 10.1.1.10 and it is listening on
TCP port 5060 and TLS port 5061, following XCAP URLs can be used:

http://10.1.1.10:5060/xcap-root/...

https://10.1.1.10:5061/xcap-root/...