kamailio/modules/cpl-c

cpl-c Module

Bogdan-Andrei Iancu

Voice Sistem SRL

Edited by

Bogdan-Andrei Iancu

Copyright � 2003 FhG FOKUS
__________________________________________________________________

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. db_table (string)
3.3. username_column (string)
3.4. domain_column (string)
3.5. cpl_xml_column (string)
3.6. cpl_bin_column (string)
3.7. cpl_dtd_file (string)
3.8. log_dir (string)
3.9. proxy_recurse (int)
3.10. proxy_route (int)
3.11. case_sensitive (int)
3.12. realm_prefix (string)
3.13. timer_avp (string)
3.14. lookup_domain (string)
3.15. lookup_append_branches (int)
3.16. use_domain (integer)

4. Functions

4.1. cpl_run_script(type,mode, [uri])
4.2. cpl_process_register()
4.3. cpl_process_register_norpl()

5. MI Commands

5.1. LOAD_CPL
5.2. REMOVE_CPL
5.3. GET_CPL

6. Installation and Running

6.1. Database setup

List of Examples

1.1. Set db_url parameter
1.2. Set db_table parameter
1.3. Set username_column parameter
1.4. Set domain_column parameter
1.5. Set cpl_xml_column parameter
1.6. Set cpl_bin_column parameter
1.7. Set cpl_dtd_file parameter
1.8. Set log_dir parameter
1.9. Set proxy_recurse parameter
1.10. Set proxy_route parameter
1.11. Set case_sensitive parameter
1.12. Set realm_prefix parameter
1.13. Set timer_avp parameter
1.14. Set lookup_domain parameter
1.15. Set lookup_append_branches parameter
1.16. Set use_domain parameter
1.17. cpl_run_script usage
1.18. cpl_process_register usage
1.19. cpl_process_register_norpl usage

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. db_table (string)
3.3. username_column (string)
3.4. domain_column (string)
3.5. cpl_xml_column (string)
3.6. cpl_bin_column (string)
3.7. cpl_dtd_file (string)
3.8. log_dir (string)
3.9. proxy_recurse (int)
3.10. proxy_route (int)
3.11. case_sensitive (int)
3.12. realm_prefix (string)
3.13. timer_avp (string)
3.14. lookup_domain (string)
3.15. lookup_append_branches (int)
3.16. use_domain (integer)

4. Functions

4.1. cpl_run_script(type,mode, [uri])
4.2. cpl_process_register()
4.3. cpl_process_register_norpl()

5. MI Commands

5.1. LOAD_CPL
5.2. REMOVE_CPL
5.3. GET_CPL

6. Installation and Running

6.1. Database setup

1. Overview

cpl-c modules implements a CPL (Call Processing Language) interpreter.
Support for uploading/downloading/removing scripts via SIP REGISTER
method is present.

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:
* any DB module- a DB module for interfacing the DB operations
(modules like mysql, postgres, dbtext, etc)
* TM (Transaction) module- used for proxying/forking requests
* SL (StateLess) module - used for sending stateless reply when
responding to REGISTER request or for sending back error responses
* USRLOC (User Location) module - used for implementing
lookup("registration") tag (adding into location set of the users'
contact)

2.2. External Libraries or Applications

The following libraries or applications must be installed before
running Kamailio with this module loaded:
* libxml2 and libxml2-devel - on some SO, these to packages are
merged into libxml2. This library contains an engine for XML
parsing, DTD validation and DOM manipulation.

3. Parameters

3.1. db_url (string)
3.2. db_table (string)
3.3. username_column (string)
3.4. domain_column (string)
3.5. cpl_xml_column (string)
3.6. cpl_bin_column (string)
3.7. cpl_dtd_file (string)
3.8. log_dir (string)
3.9. proxy_recurse (int)
3.10. proxy_route (int)
3.11. case_sensitive (int)
3.12. realm_prefix (string)
3.13. timer_avp (string)
3.14. lookup_domain (string)
3.15. lookup_append_branches (int)
3.16. use_domain (integer)

3.1. db_url (string)

A SQL URL have to be given to the module for knowing where the database
containing the table with CPL scripts is locates. If required a user
name and password can be specified for allowing the module to connect
to the database server.

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

Example 1.1. Set db_url parameter
...
modparam("cpl-c","db_url","dbdriver://username:password@dbhost/dbname")
...

3.2. db_table (string)

Indicates the name of the table that store the CPL scripts. This table
must be locate into the database specified by "db_url" parameter. For
more about the format of the CPL table please see the
modules/cpl-c/init.mysql file.

Default value is "cpl".

Example 1.2. Set db_table parameter
...
modparam("cpl-c","cpl_table","cpl")
...

3.3. username_column (string)

Indicates the name of the column used for storing the username.

Default value is "username".

Example 1.3. Set username_column parameter
...
modparam("cpl-c","username_column","username")
...

3.4. domain_column (string)

Indicates the name of the column used for storing the domain.

Default value is "domain".

Example 1.4. Set domain_column parameter
...
modparam("cpl-c","domain_column","domain")
...

3.5. cpl_xml_column (string)

Indicates the name of the column used for storing the the XML version
of the cpl script.

Default value is "cpl_xml".

Example 1.5. Set cpl_xml_column parameter
...
modparam("cpl-c","cpl_xml_column","cpl_xml")
...

3.6. cpl_bin_column (string)

Indicates the name of the column used for storing the the binary
version of the cpl script (compiled version).

Default value is "cpl_bin".

Example 1.6. Set cpl_bin_column parameter
...
modparam("cpl-c","cpl_bin_column","cpl_bin")
...

3.7. cpl_dtd_file (string)

Points to the DTD file describing the CPL grammar. The file name may
include also the path to the file. This path can be absolute or
relative (be careful the path will be relative to the starting
directory of Kamailio).

This parameter is MANDATORY!

Example 1.7. Set cpl_dtd_file parameter
...
modparam("cpl-c","cpl_dtd_file","/etc/kamailio/cpl-06.dtd")
...

3.8. log_dir (string)

Points to a directory where should be created all the log file
generated by the LOG CPL node. A log file per user will be created (on
demand) having the name username.log.

If this parameter is absent, the logging will be disabled without
generating error on execution.

Example 1.8. Set log_dir parameter
...
modparam("cpl-c","log_dir","/var/log/kamailio/cpl")
...

3.9. proxy_recurse (int)

Tells for how many time is allow to have recurse for PROXY CPL node If
it has value 2, when doing proxy, only twice the proxy action will be
re-triggered by a redirect response; the third time, the proxy
execution will end by going on REDIRECTION branch. The recurse feature
can be disable by setting this parameter to 0

Default value of this parameter is 0.

Example 1.9. Set proxy_recurse parameter
...
modparam("cpl-c","proxy_recurse",2)
...

3.10. proxy_route (int)

Before doing proxy (forward), a script route can be executed. All
modifications made by that route will be reflected only for the current
branch.

Default value of this parameter is 0 (none).

Example 1.10. Set proxy_route parameter
...
modparam("cpl-c","proxy_route",1)
...

3.11. case_sensitive (int)

Tells if the username matching should be perform case sensitive or not.
Set it to a non zero value to force a case sensitive handling of
usernames.

Default value of this parameter is 0.

Example 1.11. Set case_sensitive parameter
...
modparam("cpl-c","case_sensitive",1)
...

3.12. realm_prefix (string)

Defines a prefix for the domain part which should be ignored in
handling users and scripts.

Default value of this parameter is empty string.

Example 1.12. Set realm_prefix parameter
...
modparam("cpl-c","realm_prefix","sip.")
...

3.13. timer_avp (string)

Full specification (ID, NAME, ALIAS) of the AVP to be used to set the
value of the Final Response INVITE timeout - it's used by the TIMEOUT
attribute from the PROXY tag.

NOTE: take care and syncronize this value with the similar parameters
in TM module.

Default value of this parameter is NULL.

Example 1.13. Set timer_avp parameter
...
modparam("cpl-c","timer_avp","$avp(i:14)")
...

3.14. lookup_domain (string)

Used by lookup tag to indicate where to perform user location.
Basically this is the name of the usrloc domain (table) where the user
registrations are kept.

If set to empty string, the lookup node will be disabled - no user
location will be performed.

Default value of this parameter is NULL.

Example 1.14. Set lookup_domain parameter
...
modparam("cpl-c","lookup_domain","location")
...

3.15. lookup_append_branches (int)

Tells if the lookup tag should append branches (to do parallel forking)
if user_location lookup returns more than one contact. Set it to a non
zero value to enable parallel forking for location lookup tag.

Default value of this parameter is 0.

Example 1.15. Set lookup_append_branches parameter
...
modparam("cpl-c","lookup_append_branches",1)
...

3.16. use_domain (integer)

Indicates if the domain part of the URI should be used in user
identification (otherwise only username part will be used).

Default value is "0 (disabled)".

Example 1.16. Set use_domain parameter
...
modparam("cpl-c","use_domain",1)
...

4. Functions

4.1. cpl_run_script(type,mode, [uri])
4.2. cpl_process_register()
4.3. cpl_process_register_norpl()

4.1. cpl_run_script(type,mode, [uri])

Starts the execution of the CPL script. The user name is fetched from
new_uri or requested uri or from To header -in this order- (for
incoming execution) or from FROM header (for outgoing execution).
Regarding the stateful/stateless message processing, the function is
very flexible, being able to run in different modes (see below
the"mode" parameter). Normally this function will end script execution.
There is no guaranty that the CPL script interpretation ended when
Kamailio script ended also (for the same INVITE ;-)) - this can happen
when the CPL script does a PROXY and the script interpretation pause
after proxying and it will be resume when some reply is received (this
can happen in a different process of SER). If the function returns to
script, the SIP server should continue with the normal behavior as if
no script existed. When some error is returned, the function itself
haven't sent any SIP error reply (this can be done from script).

Meaning of the parameters is as follows:
* type - which part of the script should be run; set it to "incoming"
for having the incoming part of script executed (when an INVITE is
received) or to "outgoing" for running the outgoing part of script
(when a user is generating an INVITE - call).
* mode - sets the interpreter mode as stateless/stateful behavior.
The following modes are accepted:
+ IS_STATELESS - the current INVITE has no transaction created
yet. All replies (redirection or deny) will be done is a
stateless way. The execution will switch to stateful only when
proxy is done. So, if the function returns, will be in
stateless mode.
+ IS_STATEFUL - the current INVITE has already a transaction
associated. All signaling operations (replies or proxy) will
be done in stateful way.So, if the function returns, will be
in stateful mode.
+ FORCE_STATEFUL - the current INVITE has no transaction created
yet. All signaling operations will be done is a stateful way
(on signaling, the transaction will be created from within the
interpreter). So, if the function returns, will be in
stateless mode.
HINT: is_stateful is very difficult to manage from the routing
script (script processing can continue in stateful mode);
is_stateless is the fastest and less resources consumer
(transaction is created only if proxying is done), but there is
minimal protection against retransmissions (since replies are send
stateless); force_stateful is a good compromise - all signaling is
done stateful (retransmission protection) and in the same time, if
returning to script, it will be in stateless mode (easy to continue
the routing script execution)
* uri - optional - provide the SIP URI to be used for loading the CPL
script, instead of taking it from R-URI or headers.

This function can be used from REQUEST_ROUTE.

Example 1.17. cpl_run_script usage
...
cpl_run_script("incoming","force_stateful");
...

4.2. cpl_process_register()

This function MUST be called only for REGISTER requests. It checks if
the current REGISTER request is related or not with CPL script
upload/download/ remove. If it is, all the needed operation will be
done. For checking if the REGISTER is CPL related, the function looks
fist to "Content-Type" header. If it exists and has a the mime type set
to "application/cpl+xml" means this is a CPL script upload/remove
operation. The distinction between to case is made by looking at
"Content-Disposition" header; id its value is "script;action=store",
means it's an upload; if it's "script;action=remove", means it's a
remove operation; other values are considered to be errors. If no
"Content-Type" header is present, the function looks to "Accept" header
and if it contains the "*" or "application/cpl-xml" the request it will
be consider one for downloading CPL scripts. The functions returns to
script only if the REGISTER is not related to CPL. In other case, the
function will send by itself the necessary replies (stateless - using
sl), including for errors.

This function can be used from REQUEST_ROUTE.

Example 1.18. cpl_process_register usage
...
if (method=="REGISTER") {
cpl_process_register();
}
...

4.3. cpl_process_register_norpl()

Same as "cpl_process_register" without internally generating the reply.
All information (script) is appended to the reply but without sending
it out.

Main purpose of this function is to allow integration between CPL and
UserLocation services via same REGISTER messages.

This function can be used from REQUEST_ROUTE.

Example 1.19. cpl_process_register_norpl usage
...
if (method=="REGISTER") {
cpl_process_register();
# continue with usrloc part
save("location");
}
...

5. MI Commands

5.1. LOAD_CPL
5.2. REMOVE_CPL
5.3. GET_CPL

5.1. LOAD_CPL

For the given user, loads the XML cpl file, compiles it into binary
format and stores both format into database.

Name: LOAD_CPL

Parameters:
* username : name of the user
* cpl_filename: file name

MI FIFO Command format:
:LOAD_CPL:_reply_fifo_file_
username
cpl_filename
_empty_line_

5.2. REMOVE_CPL

For the given user, removes the entire database record (XML cpl and
binary cpl); user with empty cpl scripts are not accepted.

Name: REMOVE_CPL

Parameters:
* username : name of the user

MI FIFO Command format:
:REMOVE_CPL:_reply_fifo_file_
username
_empty_line_

5.3. GET_CPL

For the given user, returns the CPL script in XML format.

Name: GET_CPL

Parameters:
* username : name of the user

MI FIFO Command format:
:GET_CPL:_reply_fifo_file_
username
_empty_line_

6. Installation and Running

6.1. Database setup

6.1. Database setup

Before running Kamailio with cpl-c, you have to setup the database
table where the module will store the CPL scripts. For that, if the
table was not created by the installation script or you choose to
install everything by yourself you can use the cpc-create.sql SQL
script in the database directories in the kamailio/scripts folder as
template. Database and table name can be set with module parameters so
they can be changed, but the name of the columns must be as they are in
the SQL script. You can also find the complete database documentation
on the project webpage,
http://www.kamailio.org/docs/db-tables/kamailio-db-devel.html.