Presence User Agent Module Anca-Maria Vamanu voice-system.ro Edited by Anca-Maria Vamanu Copyright © 2006 voice-system.ro __________________________________________________________ Table of Contents 1. User's Guide 1.1. Overview 1.2. Dependencies 1.2.1. OpenSER Modules 1.2.2. External Libraries or Applications 1.3. Exported Parameters 1.3.1. hash_size (int) 1.3.2. db_url (str) 1.3.3. db_table (str) 1.3.4. min_expires (int) 1.3.5. default_expires (int) 1.3.6. update_period (int) 1.4. Exported Functions 1.5. Installation 2. Developer's Guide 2.1. bind_pua(pua_api_t* api) 2.2. send_publish 2.3. send_subscribe 2.4. is_dialog 2.5. register_puacb 2.6. add_event 3. Frequently Asked Questions List of Examples 1-1. Set hash_size parameter 1-2. Set db_url parameter 1-3. Set db_table parameter 1-4. Set min_expires parameter 1-5. Set default_expires parameter 1-6. Set update_period parameter 2-1. pua_api structure 2-2. pua_is_dialog usage example 2-3. register_puacb usage example 2-4. add_event usage example __________________________________________________________ Chapter 1. User's Guide 1.1. Overview This module offer the functionality of a presence user agent client, sending Subscribe and Publish messages. Now it can be used with the following modules: pua_mi and pua_usrloc, pua_bla and pua_xmpp. The pua_mi offer the possibility to publish any kind of information or subscribing to a resource through fifo. The pua_usrloc module calls a function exported by pua modules to publish elementary presence information, such as basic status "open" or "closed", for clients that do not implement client-to-server presence. Through pua_bla , BRIDGED LINE APPEARANCE features are added to openser. The pua_xmpp module represents a gateway between SIP and XMPP, so that jabber and SIP clients can exchange presence information. The module use cache to store presentity list and writes to database on timer to be able to recover upon restart. __________________________________________________________ 1.2. Dependencies 1.2.1. OpenSER Modules The following modules must be loaded before this module: * a database modules. * tm. __________________________________________________________ 1.2.2. External Libraries or Applications The following libraries or applications must be installed before running OpenSER with this module loaded: * libxml. __________________________________________________________ 1.3. Exported Parameters 1.3.1. hash_size (int) The size of the hash table used for storing Subscribe and Publish information. This parameter will be used as the power of 2 when computing table size. Default value is "9 (512)". Example 1-1. Set hash_size parameter ... modparam("pua", "hash_size", 11) ... __________________________________________________________ 1.3.2. db_url (str) Database url. Default value is "NULL". Example 1-2. Set db_url parameter ... modparam("pua", "db_url" "mysql://openser:openserrw@192.168.2.132/openser") ... __________________________________________________________ 1.3.3. db_table (str) The name of the database table. Default value is "pua". Example 1-3. Set db_table parameter ... modparam("pua", "db_table", "pua") ... __________________________________________________________ 1.3.4. min_expires (int) The inferior expires limit for both Publish and Subscribe. Default value is "0". Example 1-4. Set min_expires parameter ... modparam("pua", "min_expires", 0) ... __________________________________________________________ 1.3.5. default_expires (int) The default expires value used in case this information is not provisioned. Default value is "3600". Example 1-5. Set default_expires parameter ... modparam("pua", "default_expires", 3600) ... __________________________________________________________ 1.3.6. update_period (int) The interval at which the information in database and hash table should be updated. In the case of the hash table updating is deleting expired messages. Default value is "30". Example 1-6. Set update_period parameter ... modparam("pua", "update_period", 100) ... __________________________________________________________ 1.4. Exported Functions No function exported to be used in configuration script. __________________________________________________________ 1.5. Installation The module requires 1 table in OpenSER database: pua. The SQL syntax to create it can be found in presence_xml-create.sql script in the database directories in the openser/scripts folder. You can also find the complete database documentation on the project webpage, http://www.openser.org/docs/db-tables/openser-db-devel.html. __________________________________________________________ Chapter 2. Developer's Guide The module provides the following functions that can be used in other OpenSER modules. __________________________________________________________ 2.1. bind_pua(pua_api_t* api) This function binds the pua modules and fills the structure with the two exported function. Example 2-1. pua_api structure ... typedef struct pua_api { send_subscribe_t send_subscribe; send_publish_t send_publish; query_dialog_t is_dialog; register_puacb_t register_puacb; add_pua_event_t add_event; } pua_api_t; ... __________________________________________________________ 2.2. send_publish Field type: ... typedef int (*send_publish_t)(publ_info_t* publ); ... This function receives as a parameter a structure with Publish required information and sends a Publish message. The structure received as a parameter: ... typedef struct publ_info str id; /* (optional )a value unique for one combination of pres_uri and flag */ str* pres_uri; /* the presentity uri */ str* body; /* the body of the Publish message; can be NULL in case of an update expires*/ int expires; /* the expires value that will be used in Publish Expires header*/ int flag; /* it can be : INSERT_TYPE or UPDATE_TYPE if missing it will be established according to the result of the search in hash table*/ int source_flag; /* flag identifying the resource ; supported values: UL_PUBLISH, MI_PUBLISH, BLA_PUBLISH, XMPP_PUBLISH*/ int event; /* the event flag; supported values: PRESENCE_EVENT, BLA_EVENT, MWI_EVENT */ str content_type; /* the content_type of the body if present (optional if the same as the default value for that event)*/ str* etag; /* (optional) the value of the etag the request should match */ str* extra_headers /* (optional) extra_headers that should be added to Publish msg*/ publrpl_cb_t* cbrpl;/* callback function to be called when receiving the reply for the sent request */ void* cbparam; /* extra parameter for tha callback function */ }publ_info_t; ... The callback function type: ... typedef int (publrpl_cb_t)(struct sip_msg* reply, void* extra_param); ... __________________________________________________________ 2.3. send_subscribe Field type: ... typedef int (*send_subscribe_t)(subs_info_t* subs); ... This function receives as a parameter a structure with Subscribe required information and sends a Subscribe message. The structure received as a parameter: ... typedef struct subs_info str id; /* an id value unique for one combination of pres_uri and flag */ str* pres_uri; /* the presentity uri */ str* watcher_uri; /* the watcher uri */ str* contact; /* the uri that will be used in Contact header*/ str* remote_target; /* the uri that will be used as R-URI for the Subscribe message(not compulsory; if not set the value of the pres_uri field is used) */ str* outbound_proxy; /* the outbound_proxy to use when sending the Subscribe request*/ int event; /* the event flag; supported value: PRESENCE_EVENT, BLA_EVENT, PWINFO_EVENT*/ int expires; /* the expires value that will be used in Subscribe Expires header */ int flag; /* it can be : INSERT_TYPE or UPDATE_TYPE not compulsory */ int source_flag; /* flag identifying the resource ; supported values: MI_SUBSCRIBE, BLA_SUBSCRIBE, XMPP_SUBSCRIBE, XMPP_INITIAL_SUBS */ }subs_info_t; ... __________________________________________________________ 2.4. is_dialog Field type: ... typedef int (*query_dialog_t)(ua_pres_t* presentity); ... This function checks is the parameter corresponds to a stored Subscribe initiated dialog. Example 2-2. pua_is_dialog usage example ... if(pua_is_dialog(dialog)< 0) { LM_ERR("querying dialog\n"); goto error; } ... __________________________________________________________ 2.5. register_puacb Field type: ... typedef int (*register_puacb_t)(int types, pua_cb f, void* param ); ... This function registers a callback to be called on receiving the reply message for a sent Subscribe request. The type parameter should be set the same as the source_flag for that request. The function registered as callback for pua should be of type pua_cb , which is: typedef void (pua_cb)(ua_pres_t* hentity, struct msg_start * fl); The parameters are the dialog structure for that request and the first line of the reply message. Example 2-3. register_puacb usage example ... if(pua.register_puacb(XMPP_SUBSCRIBE, Sipreply2Xmpp, NULL)< 0) { LM_ERR("Could not register callback\n"); return -1; } ... __________________________________________________________ 2.6. add_event Field type: ... typedef int (*add_pua_event_t)(int ev_flag, char* name, char* content_type,evs_process_body_t* process_body); - ev_flag : an event flag defined as a macro in pua module - name : the event name to be used in Event request headers - content_type: the default content_type for Publish body for that event (NULL if winfo event) - process_body: function that processes the received body before using it to construct the PUBLISH request (NULL if winfo event) ... This function allows registering new events to the pua module. Now there are 4 events supported by the pua module: presence, presence;winfo, message-summary, dialog;sla. These events are registered from within the pua module. Filed type for process_body: ... typedef int (evs_process_body_t)(struct publ_info* publ, str** final_body, int ver, str* tuple); - publ : the structure received as a parameter in send_publish function ( initial body found in publ->body) - final_body: the pointer where the result(final_body) should be stored - ver : a counter for the sent Publish requests (used for winfo events) - tuple : a unique identifier for the resource; if an initial Publish it should be returned as a result and it will be stored for that record, otherwise it will be given as a parameter; ... Example 2-4. add_event usage example ... if(pua.add_event((PRESENCE_EVENT, "presence", "application/pidf+ xml", pres_process_body)< 0) { LM_ERR("Could not register new event\n"); return -1; } ... __________________________________________________________ Chapter 3. Frequently Asked Questions 3.1. Where can I find more about OpenSER? 3.2. Where can I post a question about this module? 3.3. How can I report a bug? 3.1. Where can I find more about OpenSER? Take a look at http://www.openser.org/. 3.2. Where can I post a question about this module? First at all check if your question was already answered on one of our mailing lists: * User Mailing List - http://lists.openser.org/cgi-bin/mailman/listinfo/users * Developer Mailing List - http://lists.openser.org/cgi-bin/mailman/listinfo/devel E-mails regarding any stable OpenSER release should be sent to <users@lists.openser.org> and e-mails regarding development versions should be sent to <devel@lists.openser.org>. If you want to keep the mail private, send it to <team@lists.openser.org>. 3.3. How can I report a bug? Please follow the guidelines provided at: http://sourceforge.net/tracker/?group_id=139143.