Implement the defined PUBLISH ESC API within res_sip_pubsub.

(closes issue ASTERISK-21452) Review: https://reviewboard.asterisk.org/r/2630/ git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@393262 65c4cc65-6c06-0410-ace0-fbb531ad65f3
2025-09-05 20:20:07 +00:00 · 2013-06-29 13:42:19 +00:00
parent a174aa73f6
commit f523a96635
3 changed files with 795 additions and 173 deletions
--- a/include/asterisk/res_sip_pubsub.h
+++ b/include/asterisk/res_sip_pubsub.h
@@ -29,19 +29,174 @@ struct ast_sip_endpoint;
 struct ast_datastore;
 struct ast_datastore_info;

+/*!
+ * \brief Opaque structure representing a publication
+ */
+struct ast_sip_publication;
+
+/*!
+ * \brief Callbacks that publication handlers will define
+ */
+struct ast_sip_publish_handler {
+	/*! \brief The name of the event this handler deals with */
+	const char *event_name;
+
+	/*! \brief Publications */
+	struct ao2_container *publications;
+
+	/*!
+	 * \brief Called when a PUBLISH to establish a new publication arrives.
+	 *
+	 * \param endpoint The endpoint from whom the PUBLISH arrived
+	 * \param rdata The PUBLISH request
+	 * \retval NULL PUBLISH was not accepted
+	 * \retval non-NULL New publication
+	 *
+	 * \note The callback is expected to send a response for the PUBLISH in success cases.
+	 */
+	struct ast_sip_publication *(*new_publication)(struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata);
+
+	/*!
+	 * \brief Called when a PUBLISH for an existing publication arrives.
+	 *
+	 * This PUBLISH may be intending to change state or it may be simply renewing
+	 * the publication since the publication is nearing expiration. The callback
+	 * is expected to send a response to the PUBLISH.
+	 *
+	 * \param pub The publication on which the PUBLISH arrived
+	 * \param rdata The PUBLISH request
+	 * \retval 0 Publication was accepted
+	 * \retval non-zero Publication was denied
+	 *
+	 * \note The callback is expected to send a response for the PUBLISH.
+	 */
+	int (*publish_refresh)(struct ast_sip_publication *pub, pjsip_rx_data *rdata);
+
+	/*!
+	 * \brief Called when a publication has reached its expiration.
+	 */
+	void (*publish_expire)(struct ast_sip_publication *pub);
+
+	/*!
+	 * \brief Called when a PUBLISH arrives to terminate a publication.
+	 *
+	 * \param pub The publication that is terminating
+	 * \param rdata The PUBLISH request terminating the publication
+	 *
+	 * \note The callback is expected to send a response for the PUBLISH.
+	 */
+	void (*publish_termination)(struct ast_sip_publication *pub, pjsip_rx_data *rdata);
+
+	AST_LIST_ENTRY(ast_sip_publish_handler) next;
+};
+
+/*!
+ * \brief Create a new publication
+ *
+ * Publication handlers should call this when a PUBLISH arrives to establish a new publication.
+ *
+ * \param endpoint The endpoint from whom the PUBLISHes arrive
+ * \param rdata The PUBLISH that established the publication
+ * \retval NULL Failed to create a publication
+ * \retval non-NULL The newly-created publication
+ */
+struct ast_sip_publication *ast_sip_create_publication(struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata);
+
+/*!
+ * \brief Given a publication, get the associated endpoint
+ *
+ * \param pub The publication
+ * \retval NULL Failure
+ * \retval non-NULL The associated endpoint
+ */
+struct ast_sip_endpoint *ast_sip_publication_get_endpoint(struct ast_sip_publication *pub);
+
+/*!
+ * \brief Create a response to an inbound PUBLISH
+ *
+ * The created response must be sent using ast_sip_publication_send_response
+ *
+ * \param pub The publication
+ * \param status code The status code to place in the response
+ * \param rdata The request to which the response is being made
+ * \param[out] tdata The created response
+ */
+int ast_sip_publication_create_response(struct ast_sip_publication *pub, int status_code, pjsip_rx_data *rdata,
+	pjsip_tx_data **tdata);
+
+/*!
+ * \brief Send a response for an inbound PUBLISH
+ *
+ * \param pub The publication
+ * \param rdata The request to which the response was made
+ * \param tdata The response to the request
+ */
+pj_status_t ast_sip_publication_send_response(struct ast_sip_publication *pub, pjsip_rx_data *rdata,
+	pjsip_tx_data *tdata);
+
+/*!
+ * \brief Register a publish handler
+ *
+ * \retval 0 Handler was registered successfully
+ * \retval non-zero Handler was not registered successfully
+ */
+int ast_sip_register_publish_handler(struct ast_sip_publish_handler *handler);
+
+/*!
+ * \brief Unregister a publish handler
+ */
+void ast_sip_unregister_publish_handler(struct ast_sip_publish_handler *handler);
+
+/*!
+ * \brief Add a datastore to a SIP publication
+ *
+ * Note that SIP uses reference counted datastores. The datastore passed into this function
+ * must have been allocated using ao2_alloc() or there will be serious problems.
+ *
+ * \param publication The publication to add the datastore to
+ * \param datastore The datastore to be added to the subscription
+ * \retval 0 Success
+ * \retval -1 Failure
+ */
+int ast_sip_publication_add_datastore(struct ast_sip_publication *publication, struct ast_datastore *datastore);
+
+/*!
+ * \brief Retrieve a publication datastore
+ *
+ * The datastore retrieved will have its reference count incremented. When the caller is done
+ * with the datastore, the reference counted needs to be decremented using ao2_ref().
+ *
+ * \param publication The publication from which to retrieve the datastore
+ * \param name The name of the datastore to retrieve
+ * \retval NULL Failed to find the specified datastore
+ * \retval non-NULL The specified datastore
+ */
+struct ast_datastore *ast_sip_publication_get_datastore(struct ast_sip_publication *publication, const char *name);
+
+/*!
+ * \brief Remove a publication datastore from the publication
+ *
+ * This operation may cause the datastore's free() callback to be called if the reference
+ * count reaches zero.
+ *
+ * \param publication The publication to remove the datastore from
+ * \param name The name of the datastore to remove
+ */
+void ast_sip_publication_remove_datastore(struct ast_sip_publication *publication, const char *name);
+
 /*!
 * \brief Opaque structure representing an RFC 3265 SIP subscription
 */
 struct ast_sip_subscription;
- 
+
 /*!
 * \brief Role for the subscription that is being created
 */
 enum ast_sip_subscription_role {
-    /* Sending SUBSCRIBEs, receiving NOTIFYs */
-    AST_SIP_SUBSCRIBER,
-    /* Sending NOTIFYs, receiving SUBSCRIBEs */
-    AST_SIP_NOTIFIER,
+	/* Sending SUBSCRIBEs, receiving NOTIFYs */
+	AST_SIP_SUBSCRIBER,
+	/* Sending NOTIFYs, receiving SUBSCRIBEs */
+	AST_SIP_NOTIFIER,
 };

 /*!
@@ -56,147 +211,147 @@ enum ast_sip_subscription_role {
 * not provide it with any additional data.
 */
 struct ast_sip_subscription_response_data {
-    /*! Status code of the response */
-    int status_code;
-    /*! Optional status text */
-    const char *status_text;
-    /*! Optional additional headers to add to the response */
-    struct ast_variable *headers;
-    /*! Optional body to add to the response */
-    struct ast_sip_body *body;
+	/*! Status code of the response */
+	int status_code;
+	/*! Optional status text */
+	const char *status_text;
+	/*! Optional additional headers to add to the response */
+	struct ast_variable *headers;
+	/*! Optional body to add to the response */
+	struct ast_sip_body *body;
 };

 #define AST_SIP_MAX_ACCEPT 32

 struct ast_sip_subscription_handler {
-    /*! The name of the event this handler deals with */
-    const char *event_name;
-    /*! The types of body this handler accepts */
-    const char *accept[AST_SIP_MAX_ACCEPT];
- 
-    /*!
-     * \brief Called when a subscription is to be destroyed
-     *
-     * This is a subscriber and notifier callback.
-     *
-     * The handler is not expected to send any sort of requests or responses
-     * during this callback. The handler MUST, however, begin the destruction
+	/*! The name of the event this handler deals with */
+	const char *event_name;
+	/*! The types of body this handler accepts */
+	const char *accept[AST_SIP_MAX_ACCEPT];
+
+	/*!
+	 * \brief Called when a subscription is to be destroyed
+	 *
+	 * This is a subscriber and notifier callback.
+	 *
+	 * The handler is not expected to send any sort of requests or responses
+	 * during this callback. The handler MUST, however, begin the destruction
 	 * process for the subscription during this callback.
-     */
+	 */
   void (*subscription_shutdown)(struct ast_sip_subscription *subscription);
- 
-    /*!
-     * \brief Called when a SUBSCRIBE arrives in order to create a new subscription
-     *
-     * This is a notifier callback.
-     *
-     * If the notifier wishes to accept the subscription, then it can create
-     * a new ast_sip_subscription to do so. 
-     *
-     * If the notifier chooses to create a new subscription, then it must accept
-     * the incoming subscription using pjsip_evsub_accept() and it must also
-     * send an initial NOTIFY with the current subscription state.
-     *
-     * \param endpoint The endpoint from which we received the SUBSCRIBE
-     * \param rdata The SUBSCRIBE request
-     * \retval NULL The SUBSCRIBE has not been accepted
-     * \retval non-NULL The newly-created subscription
-     */
-    struct ast_sip_subscription *(*new_subscribe)(struct ast_sip_endpoint *endpoint,
-            pjsip_rx_data *rdata);
- 
-    /*!
-     * \brief Called when an endpoint renews a subscription.
-     *
-     * This is a notifier callback.
-     *
-     * Because of the way that the PJSIP evsub framework works, it will automatically
-     * send a response to the SUBSCRIBE. However, the subscription handler must send
+
+	/*!
+	 * \brief Called when a SUBSCRIBE arrives in order to create a new subscription
+	 *
+	 * This is a notifier callback.
+	 *
+	 * If the notifier wishes to accept the subscription, then it can create
+	 * a new ast_sip_subscription to do so.
+	 *
+	 * If the notifier chooses to create a new subscription, then it must accept
+	 * the incoming subscription using pjsip_evsub_accept() and it must also
+	 * send an initial NOTIFY with the current subscription state.
+	 *
+	 * \param endpoint The endpoint from which we received the SUBSCRIBE
+	 * \param rdata The SUBSCRIBE request
+	 * \retval NULL The SUBSCRIBE has not been accepted
+	 * \retval non-NULL The newly-created subscription
+	 */
+	struct ast_sip_subscription *(*new_subscribe)(struct ast_sip_endpoint *endpoint,
+			pjsip_rx_data *rdata);
+
+	/*!
+	 * \brief Called when an endpoint renews a subscription.
+	 *
+	 * This is a notifier callback.
+	 *
+	 * Because of the way that the PJSIP evsub framework works, it will automatically
+	 * send a response to the SUBSCRIBE. However, the subscription handler must send
 	 * a NOTIFY with the current subscription state when this callback is called.
 	 *
 	 * The response_data that is passed into this callback is used to craft what should
 	 * be in the response to the incoming SUBSCRIBE. It is initialized with a 200 status
 	 * code and all other parameters are empty.
-     *
-     * \param sub The subscription that is being renewed
-     * \param rdata The SUBSCRIBE request in question
+	 *
+	 * \param sub The subscription that is being renewed
+	 * \param rdata The SUBSCRIBE request in question
 	 * \param[out] response_data Data pertaining to the SIP response that should be
 	 * sent to the SUBSCRIBE
-     */
-    void (*resubscribe)(struct ast_sip_subscription *sub,
-            pjsip_rx_data *rdata, struct ast_sip_subscription_response_data *response_data);
- 
-    /*!
-     * \brief Called when a subscription times out.
-     *
-     * This is a notifier callback
-     *
-     * This indicates that the subscription has timed out. The subscription handler is
-     * expected to send a NOTIFY that terminates the subscription.
-     *
-     * \param sub The subscription that has timed out
-     */
-    void (*subscription_timeout)(struct ast_sip_subscription *sub);
- 
-    /*!
-     * \brief Called when a subscription is terminated via a SUBSCRIBE or NOTIFY request
-     *
-     * This is a notifier and subscriber callback.
-     *
-     * The PJSIP subscription framework will automatically send the response to the
-     * request. If a notifier receives this callback, then the subscription handler
+	 */
+	void (*resubscribe)(struct ast_sip_subscription *sub,
+			pjsip_rx_data *rdata, struct ast_sip_subscription_response_data *response_data);
+
+	/*!
+	 * \brief Called when a subscription times out.
+	 *
+	 * This is a notifier callback
+	 *
+	 * This indicates that the subscription has timed out. The subscription handler is
+	 * expected to send a NOTIFY that terminates the subscription.
+	 *
+	 * \param sub The subscription that has timed out
+	 */
+	void (*subscription_timeout)(struct ast_sip_subscription *sub);
+
+	/*!
+	 * \brief Called when a subscription is terminated via a SUBSCRIBE or NOTIFY request
+	 *
+	 * This is a notifier and subscriber callback.
+	 *
+	 * The PJSIP subscription framework will automatically send the response to the
+	 * request. If a notifier receives this callback, then the subscription handler
 	 * is expected to send a final NOTIFY to terminate the subscription.
-     *
-     * \param sub The subscription being terminated
-     * \param rdata The request that terminated the subscription
-     */
-    void (*subscription_terminated)(struct ast_sip_subscription *sub, pjsip_rx_data *rdata);
- 
-    /*!
-     * \brief Called when a subscription handler's outbound NOTIFY receives a response
-     *
-     * This is a notifier callback.
-     *
-     * \param sub The subscription
-     * \param rdata The NOTIFY response
-     */
-    void (*notify_response)(struct ast_sip_subscription *sub, pjsip_rx_data *rdata);
- 
-    /*!
-     * \brief Called when a subscription handler receives an inbound NOTIFY
-     *
-     * This is a subscriber callback.
-     *
-     * Because of the way that the PJSIP evsub framework works, it will automatically
-     * send a response to the NOTIFY. By default this will be a 200 OK response, but
-     * this callback can change details of the response by returning response data
-     * to use.
+	 *
+	 * \param sub The subscription being terminated
+	 * \param rdata The request that terminated the subscription
+	 */
+	void (*subscription_terminated)(struct ast_sip_subscription *sub, pjsip_rx_data *rdata);
+
+	/*!
+	 * \brief Called when a subscription handler's outbound NOTIFY receives a response
+	 *
+	 * This is a notifier callback.
+	 *
+	 * \param sub The subscription
+	 * \param rdata The NOTIFY response
+	 */
+	void (*notify_response)(struct ast_sip_subscription *sub, pjsip_rx_data *rdata);
+
+	/*!
+	 * \brief Called when a subscription handler receives an inbound NOTIFY
+	 *
+	 * This is a subscriber callback.
+	 *
+	 * Because of the way that the PJSIP evsub framework works, it will automatically
+	 * send a response to the NOTIFY. By default this will be a 200 OK response, but
+	 * this callback can change details of the response by returning response data
+	 * to use.
 	 *
 	 * The response_data that is passed into this callback is used to craft what should
 	 * be in the response to the incoming SUBSCRIBE. It is initialized with a 200 status
 	 * code and all other parameters are empty.
-     *
-     * \param sub The subscription
-     * \param rdata The NOTIFY request
+	 *
+	 * \param sub The subscription
+	 * \param rdata The NOTIFY request
 	 * \param[out] response_data Data pertaining to the SIP response that should be
 	 * sent to the SUBSCRIBE
-     */
-    void (*notify_request)(struct ast_sip_subscription *sub,
-            pjsip_rx_data *rdata, struct ast_sip_subscription_response_data *response_data);
- 
-    /*!
-     * \brief Called when it is time for a subscriber to resubscribe
-     *
-     * This is a subscriber callback.
-     *
-     * The subscriber can reresh the subscription using the pjsip_evsub_initiate()
-     * function.
-     *
-     * \param sub The subscription to refresh
-     * \retval 0 Success
-     * \retval non-zero Failure
-     */
-    int (*refresh_subscription)(struct ast_sip_subscription *sub);
+	 */
+	void (*notify_request)(struct ast_sip_subscription *sub,
+			pjsip_rx_data *rdata, struct ast_sip_subscription_response_data *response_data);
+
+	/*!
+	 * \brief Called when it is time for a subscriber to resubscribe
+	 *
+	 * This is a subscriber callback.
+	 *
+	 * The subscriber can reresh the subscription using the pjsip_evsub_initiate()
+	 * function.
+	 *
+	 * \param sub The subscription to refresh
+	 * \retval 0 Success
+	 * \retval non-zero Failure
+	 */
+	int (*refresh_subscription)(struct ast_sip_subscription *sub);
 	AST_LIST_ENTRY(ast_sip_subscription_handler) next;
 };

@@ -221,9 +376,9 @@ struct ast_sip_subscription_handler {
 * \param rdata If acting as a notifier, the SUBSCRIBE request that triggered subscription creation
 */
 struct ast_sip_subscription *ast_sip_create_subscription(const struct ast_sip_subscription_handler *handler,
-        enum ast_sip_subscription_role role, struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata);
- 
- 
+		enum ast_sip_subscription_role role, struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata);
+
+
 /*!
 * \brief Get the endpoint that is associated with this subscription
 *
@@ -234,7 +389,7 @@ struct ast_sip_subscription *ast_sip_create_subscription(const struct ast_sip_su
 * \retval non-NULL The endpoint
 */
 struct ast_sip_endpoint *ast_sip_subscription_get_endpoint(struct ast_sip_subscription *sub);
- 
+
 /*!
 * \brief Get the serializer for the subscription
 *
@@ -246,7 +401,7 @@ struct ast_sip_endpoint *ast_sip_subscription_get_endpoint(struct ast_sip_subscr
 * \retval non-NULL The subscription's serializer
 */
 struct ast_taskprocessor *ast_sip_subscription_get_serializer(struct ast_sip_subscription *sub);
- 
+
 /*!
 * \brief Get the underlying PJSIP evsub structure
 *
@@ -289,7 +444,7 @@ pjsip_dialog *ast_sip_subscription_get_dlg(struct ast_sip_subscription *sub);
 * \retval non-zero Failure
 */
 int ast_sip_subscription_send_request(struct ast_sip_subscription *sub, pjsip_tx_data *tdata);
- 
+
 /*!
 * \brief Alternative for ast_datastore_alloc()
 *
@@ -307,7 +462,7 @@ int ast_sip_subscription_send_request(struct ast_sip_subscription *sub, pjsip_tx
 * \retval non-NULL Newly allocated datastore
 */
 struct ast_datastore *ast_sip_subscription_alloc_datastore(const struct ast_datastore_info *info, const char *uid);
- 
+
 /*!
 * \brief Add a datastore to a SIP subscription
 *
@@ -320,7 +475,7 @@ struct ast_datastore *ast_sip_subscription_alloc_datastore(const struct ast_data
 * \retval -1 Failure
 */
 int ast_sip_subscription_add_datastore(struct ast_sip_subscription *subscription, struct ast_datastore *datastore);
- 
+
 /*!
 * \brief Retrieve a subscription datastore
 *
@@ -333,7 +488,7 @@ int ast_sip_subscription_add_datastore(struct ast_sip_subscription *subscription
 * \retval non-NULL The specified datastore
 */
 struct ast_datastore *ast_sip_subscription_get_datastore(struct ast_sip_subscription *subscription, const char *name);
- 
+
 /*!
 * \brief Remove a subscription datastore from the subscription
 *
@@ -344,7 +499,7 @@ struct ast_datastore *ast_sip_subscription_get_datastore(struct ast_sip_subscrip
 * \param name The name of the datastore to remove
 */
 void ast_sip_subscription_remove_datastore(struct ast_sip_subscription *subscription, const char *name);
- 
+
 /*!
 * \brief Register a subscription handler
 *
@@ -352,7 +507,7 @@ void ast_sip_subscription_remove_datastore(struct ast_sip_subscription *subscrip
 * \retval non-zero Handler was not registered successfully
 */
 int ast_sip_register_subscription_handler(struct ast_sip_subscription_handler *handler);
- 
+
 /*!
 * \brief Unregister a subscription handler
 */
--- a/res/res_sip_pubsub.c
+++ b/res/res_sip_pubsub.c
@@ -38,14 +38,111 @@
 #include "asterisk/datastore.h"
 #include "asterisk/uuid.h"
 #include "asterisk/taskprocessor.h"
+#include "asterisk/sched.h"
 #include "asterisk/res_sip.h"

-static pj_bool_t sub_on_rx_request(pjsip_rx_data *rdata);
+static pj_bool_t pubsub_on_rx_request(pjsip_rx_data *rdata);

-static struct pjsip_module sub_module = {
+static struct pjsip_module pubsub_module = {
 	.name = { "PubSub Module", 13 },
 	.priority = PJSIP_MOD_PRIORITY_APPLICATION,
-	.on_rx_request = sub_on_rx_request,
+	.on_rx_request = pubsub_on_rx_request,
+};
+
+static const pj_str_t str_event_name = { "Event", 5 };
+
+/*! \brief Scheduler used for automatically expiring publications */
+static struct ast_sched_context *sched;
+
+/*! \brief Number of buckets for publications (on a per handler) */
+#define PUBLICATIONS_BUCKETS 37
+
+/*! \brief Default expiration time for PUBLISH if one is not specified */
+#define DEFAULT_PUBLISH_EXPIRES 3600
+
+/*! \brief Defined method for PUBLISH */
+const pjsip_method pjsip_publish_method =
+{
+	PJSIP_OTHER_METHOD,
+	{ "PUBLISH", 7 }
+};
+
+/*!
+ * \brief The types of PUBLISH messages defined in RFC 3903
+ */
+enum sip_publish_type {
+	/*!
+	 * \brief Unknown
+	 *
+	 * \details
+	 * This actually is not defined in RFC 3903. We use this as a constant
+	 * to indicate that an incoming PUBLISH does not fit into any of the
+	 * other categories and is thus invalid.
+	 */
+	SIP_PUBLISH_UNKNOWN,
+
+	/*!
+	 * \brief Initial
+	 *
+	 * \details
+	 * The first PUBLISH sent. This will contain a non-zero Expires header
+	 * as well as a body that indicates the current state of the endpoint
+	 * that has sent the message. The initial PUBLISH is the only type
+	 * of PUBLISH to not contain a Sip-If-Match header in it.
+	 */
+	SIP_PUBLISH_INITIAL,
+
+	/*!
+	 * \brief Refresh
+	 *
+	 * \details
+	 * Used to keep a published state from expiring. This will contain a
+	 * non-zero Expires header but no body since its purpose is not to
+	 * update state.
+	 */
+	SIP_PUBLISH_REFRESH,
+
+	/*!
+	 * \brief Modify
+	 *
+	 * \details
+	 * Used to change state from its previous value. This will contain
+	 * a body updating the published state. May or may not contain an
+	 * Expires header.
+	 */
+	SIP_PUBLISH_MODIFY,
+
+	/*!
+	 * \brief Remove
+	 *
+	 * \details
+	 * Used to remove published state from an ESC. This will contain
+	 * an Expires header set to 0 and likely no body.
+	 */
+	SIP_PUBLISH_REMOVE,
+};
+
+/*!
+ * Used to create new entity IDs by ESCs.
+ */
+static int esc_etag_counter;
+
+/*!
+ * \brief Structure representing a SIP publication
+ */
+struct ast_sip_publication {
+	/*! Publication datastores set up by handlers */
+	struct ao2_container *datastores;
+	/*! \brief Entity tag for the publication */
+	int entity_tag;
+	/*! \brief Handler for this publication */
+	struct ast_sip_publish_handler *handler;
+	/*! \brief The endpoint with which the subscription is communicating */
+	struct ast_sip_endpoint *endpoint;
+	/*! \brief Expiration time of the publication */
+	int expires;
+	/*! \brief Scheduled item for expiration of publication */
+	int sched_id;
 };

 /*!
@@ -114,7 +211,7 @@ static void subscription_destructor(void *obj)
 		 * remove the serializer will be successful.
 		 */
 		ast_sip_dialog_set_serializer(sub->dlg, NULL);
-		pjsip_dlg_dec_session(sub->dlg, &sub_module);
+		pjsip_dlg_dec_session(sub->dlg, &pubsub_module);
 	}
 	ast_taskprocessor_unreference(sub->serializer);
 }
@@ -165,7 +262,7 @@ static pjsip_evsub *allocate_evsub(const char *event, enum ast_sip_subscription_
 }

 struct ast_sip_subscription *ast_sip_create_subscription(const struct ast_sip_subscription_handler *handler,
-        enum ast_sip_subscription_role role, struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata)
+		enum ast_sip_subscription_role role, struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata)
 {
 	struct ast_sip_subscription *sub = ao2_alloc(sizeof(*sub), subscription_destructor);
 	pjsip_dialog *dlg;
@@ -207,23 +304,23 @@ struct ast_sip_subscription *ast_sip_create_subscription(const struct ast_sip_su
 	/* We keep a reference to the dialog until our subscription is destroyed. See
 	 * the subscription_destructor for more details
 	 */
-	pjsip_dlg_inc_session(dlg, &sub_module);
+	pjsip_dlg_inc_session(dlg, &pubsub_module);
 	sub->dlg = dlg;
 	ast_sip_dialog_set_serializer(dlg, sub->serializer);
-	pjsip_evsub_set_mod_data(sub->evsub, sub_module.id, sub);
+	pjsip_evsub_set_mod_data(sub->evsub, pubsub_module.id, sub);
 	ao2_ref(endpoint, +1);
 	sub->endpoint = endpoint;
 	sub->handler = handler;
 	return sub;
 }
- 
+
 struct ast_sip_endpoint *ast_sip_subscription_get_endpoint(struct ast_sip_subscription *sub)
 {
 	ast_assert(sub->endpoint != NULL);
 	ao2_ref(sub->endpoint, +1);
 	return sub->endpoint;
 }
- 
+
 struct ast_taskprocessor *ast_sip_subscription_get_serializer(struct ast_sip_subscription *sub)
 {
 	ast_assert(sub->serializer != NULL);
@@ -294,12 +391,12 @@ struct ast_datastore *ast_sip_subscription_alloc_datastore(const struct ast_data
 	ao2_ref(datastore, +1);
 	return datastore;
 }
- 
+
 int ast_sip_subscription_add_datastore(struct ast_sip_subscription *subscription, struct ast_datastore *datastore)
 {
 	ast_assert(datastore != NULL);
 	ast_assert(datastore->info != NULL);
-	ast_assert(ast_strlen_zero(datastore->uid) == 0);
+	ast_assert(!ast_strlen_zero(datastore->uid));

 	if (!ao2_link(subscription->datastores, datastore)) {
 		return -1;
@@ -317,16 +414,100 @@ void ast_sip_subscription_remove_datastore(struct ast_sip_subscription *subscrip
 	ao2_callback(subscription->datastores, OBJ_KEY | OBJ_UNLINK | OBJ_NODATA, NULL, (void *) name);
 }

+int ast_sip_publication_add_datastore(struct ast_sip_publication *publication, struct ast_datastore *datastore)
+{
+	ast_assert(datastore != NULL);
+	ast_assert(datastore->info != NULL);
+	ast_assert(!ast_strlen_zero(datastore->uid));
+
+	if (!ao2_link(publication->datastores, datastore)) {
+		return -1;
+	}
+	return 0;
+}
+
+struct ast_datastore *ast_sip_publication_get_datastore(struct ast_sip_publication *publication, const char *name)
+{
+	return ao2_find(publication->datastores, name, OBJ_KEY);
+}
+
+void ast_sip_publication_remove_datastore(struct ast_sip_publication *publication, const char *name)
+{
+	ao2_callback(publication->datastores, OBJ_KEY | OBJ_UNLINK | OBJ_NODATA, NULL, (void *) name);
+}
+
+AST_RWLIST_HEAD_STATIC(publish_handlers, ast_sip_publish_handler);
+
+static int publication_hash_fn(const void *obj, const int flags)
+{
+	const struct ast_sip_publication *publication = obj;
+	const int *entity_tag = obj;
+
+	return flags & OBJ_KEY ? *entity_tag : publication->entity_tag;
+}
+
+static int publication_cmp_fn(void *obj, void *arg, int flags)
+{
+	const struct ast_sip_publication *publication1 = obj;
+	const struct ast_sip_publication *publication2 = arg;
+	const int *entity_tag = arg;
+
+	return (publication1->entity_tag == (flags & OBJ_KEY ? *entity_tag : publication2->entity_tag) ?
+		CMP_MATCH | CMP_STOP : 0);
+}
+
+static void publish_add_handler(struct ast_sip_publish_handler *handler)
+{
+	SCOPED_LOCK(lock, &publish_handlers, AST_RWLIST_WRLOCK, AST_RWLIST_UNLOCK);
+	AST_RWLIST_INSERT_TAIL(&publish_handlers, handler, next);
+}
+
+int ast_sip_register_publish_handler(struct ast_sip_publish_handler *handler)
+{
+	if (ast_strlen_zero(handler->event_name)) {
+		ast_log(LOG_ERROR, "No event package specified for publish handler. Cannot register\n");
+		return -1;
+	}
+
+	if (!(handler->publications = ao2_container_alloc(PUBLICATIONS_BUCKETS,
+		publication_hash_fn, publication_cmp_fn))) {
+		ast_log(LOG_ERROR, "Could not allocate publications container for event '%s'\n",
+			handler->event_name);
+		return -1;
+	}
+
+	publish_add_handler(handler);
+
+	ast_module_ref(ast_module_info->self);
+
+	return 0;
+}
+
+void ast_sip_unregister_publish_handler(struct ast_sip_publish_handler *handler)
+{
+	struct ast_sip_publish_handler *iter;
+	SCOPED_LOCK(lock, &publish_handlers, AST_RWLIST_WRLOCK, AST_RWLIST_UNLOCK);
+	AST_RWLIST_TRAVERSE_SAFE_BEGIN(&publish_handlers, iter, next) {
+		if (handler == iter) {
+			AST_RWLIST_REMOVE_CURRENT(next);
+			ao2_cleanup(handler->publications);
+			ast_module_unref(ast_module_info->self);
+			break;
+		}
+	}
+	AST_RWLIST_TRAVERSE_SAFE_END;
+}
+
 AST_RWLIST_HEAD_STATIC(subscription_handlers, ast_sip_subscription_handler);

-static void add_handler(struct ast_sip_subscription_handler *handler)
+static void sub_add_handler(struct ast_sip_subscription_handler *handler)
 {
 	SCOPED_LOCK(lock, &subscription_handlers, AST_RWLIST_WRLOCK, AST_RWLIST_UNLOCK);
 	AST_RWLIST_INSERT_TAIL(&subscription_handlers, handler, next);
 	ast_module_ref(ast_module_info->self);
 }

-static int handler_exists_for_event_name(const char *event_name)
+static int sub_handler_exists_for_event_name(const char *event_name)
 {
 	struct ast_sip_subscription_handler *iter;
 	SCOPED_LOCK(lock, &subscription_handlers, AST_RWLIST_RDLOCK, AST_RWLIST_UNLOCK);
@@ -358,7 +539,7 @@ int ast_sip_register_subscription_handler(struct ast_sip_subscription_handler *h
 		pj_cstr(&accept[i], handler->accept[i]);
 	}

-	if (!handler_exists_for_event_name(handler->event_name)) {
+	if (!sub_handler_exists_for_event_name(handler->event_name)) {
 		pj_str_t event;

 		pj_cstr(&event, handler->event_name);
@@ -366,14 +547,14 @@ int ast_sip_register_subscription_handler(struct ast_sip_subscription_handler *h
 		if (!strcmp(handler->event_name, "message-summary")) {
 			pjsip_mwi_init_module(ast_sip_get_pjsip_endpoint(), pjsip_evsub_instance());
 		} else {
-			pjsip_evsub_register_pkg(&sub_module, &event, DEFAULT_EXPIRES, i, accept);
+			pjsip_evsub_register_pkg(&pubsub_module, &event, DEFAULT_EXPIRES, i, accept);
 		}
 	} else {
-		pjsip_endpt_add_capability(ast_sip_get_pjsip_endpoint(), &sub_module, PJSIP_H_ACCEPT, NULL,
+		pjsip_endpt_add_capability(ast_sip_get_pjsip_endpoint(), &pubsub_module, PJSIP_H_ACCEPT, NULL,
 			i, accept);
 	}

-	add_handler(handler);
+	sub_add_handler(handler);
 	return 0;
 }

@@ -391,7 +572,7 @@ void ast_sip_unregister_subscription_handler(struct ast_sip_subscription_handler
 	AST_RWLIST_TRAVERSE_SAFE_END;
 }

-static struct ast_sip_subscription_handler *find_handler(const char *event, char accept[AST_SIP_MAX_ACCEPT][64], size_t num_accept)
+static struct ast_sip_subscription_handler *find_sub_handler(const char *event, char accept[AST_SIP_MAX_ACCEPT][64], size_t num_accept)
 {
 	struct ast_sip_subscription_handler *iter;
 	int match = 0;
@@ -429,9 +610,8 @@ static struct ast_sip_subscription_handler *find_handler(const char *event, char
 	return iter;
 }

-static pj_bool_t sub_on_rx_request(pjsip_rx_data *rdata)
+static pj_bool_t pubsub_on_rx_subscribe_request(pjsip_rx_data *rdata)
 {
-	static const pj_str_t event_name = { "Event", 5 };
 	char event[32];
 	char accept[AST_SIP_MAX_ACCEPT][64];
 	pjsip_accept_hdr *accept_header;
@@ -441,14 +621,10 @@ static pj_bool_t sub_on_rx_request(pjsip_rx_data *rdata)
 	struct ast_sip_subscription *sub;
 	int i;

-	if (pjsip_method_cmp(&rdata->msg_info.msg->line.req.method, pjsip_get_subscribe_method())) {
-		return PJ_FALSE;
-	}
-
 	endpoint = ast_pjsip_rdata_get_endpoint(rdata);
 	ast_assert(endpoint != NULL);

-	event_header = pjsip_msg_find_hdr_by_name(rdata->msg_info.msg, &event_name, rdata->msg_info.msg->hdr.next);
+	event_header = pjsip_msg_find_hdr_by_name(rdata->msg_info.msg, &str_event_name, rdata->msg_info.msg->hdr.next);
 	if (!event_header) {
 		ast_log(LOG_WARNING, "Incoming SUBSCRIBE request with no Event header\n");
 		pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 489, NULL, NULL, NULL);
@@ -467,9 +643,9 @@ static pj_bool_t sub_on_rx_request(pjsip_rx_data *rdata)
 		ast_copy_pj_str(accept[i], &accept_header->values[i], sizeof(accept[i]));
 	}

-	handler = find_handler(event, accept, accept_header->count);
+	handler = find_sub_handler(event, accept, accept_header->count);
 	if (!handler) {
-		ast_log(LOG_WARNING, "No registered handler for event %s\n", event);
+		ast_log(LOG_WARNING, "No registered subscribe handler for event %s\n", event);
 		pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 489, NULL, NULL, NULL);
 		return PJ_TRUE;
 	}
@@ -492,6 +668,265 @@ static pj_bool_t sub_on_rx_request(pjsip_rx_data *rdata)
 	return PJ_TRUE;
 }

+static struct ast_sip_publish_handler *find_pub_handler(const char *event)
+{
+	struct ast_sip_publish_handler *iter = NULL;
+	SCOPED_LOCK(lock, &publish_handlers, AST_RWLIST_RDLOCK, AST_RWLIST_UNLOCK);
+
+	AST_RWLIST_TRAVERSE(&publish_handlers, iter, next) {
+		if (strcmp(event, iter->event_name)) {
+			ast_debug(3, "Event %s does not match %s\n", event, iter->event_name);
+			continue;
+		}
+		ast_debug(3, "Event name match: %s = %s\n", event, iter->event_name);
+		break;
+	}
+
+	return iter;
+}
+
+static enum sip_publish_type determine_sip_publish_type(pjsip_rx_data *rdata,
+	pjsip_generic_string_hdr *etag_hdr, int *expires, int *entity_id)
+{
+	pjsip_expires_hdr *expires_hdr = pjsip_msg_find_hdr(rdata->msg_info.msg, PJSIP_H_EXPIRES, NULL);
+
+	if (etag_hdr) {
+		char etag[pj_strlen(&etag_hdr->hvalue) + 1];
+
+		ast_copy_pj_str(etag, &etag_hdr->hvalue, sizeof(etag));
+
+		if (sscanf(etag, "%30d", entity_id) != 1) {
+			return SIP_PUBLISH_UNKNOWN;
+		}
+	}
+
+	*expires = expires_hdr ? expires_hdr->ivalue : DEFAULT_PUBLISH_EXPIRES;
+
+	if (!(*expires)) {
+		return SIP_PUBLISH_REMOVE;
+	} else if (!etag_hdr && rdata->msg_info.msg->body) {
+		return SIP_PUBLISH_INITIAL;
+	} else if (etag_hdr && !rdata->msg_info.msg->body) {
+		return SIP_PUBLISH_REFRESH;
+	} else if (etag_hdr && rdata->msg_info.msg->body) {
+		return SIP_PUBLISH_MODIFY;
+	}
+
+	return SIP_PUBLISH_UNKNOWN;
+}
+
+static struct ast_sip_publication *publish_request_initial(struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata,
+	struct ast_sip_publish_handler *handler)
+{
+	struct ast_sip_publication *publication = handler->new_publication(endpoint, rdata);
+
+	if (!publication) {
+		pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 503, NULL, NULL, NULL);
+		return NULL;
+	}
+
+	publication->handler = handler;
+
+	return publication;
+}
+
+static int publish_expire_callback(void *data)
+{
+	RAII_VAR(struct ast_sip_publication *, publication, data, ao2_cleanup);
+
+	publication->handler->publish_expire(publication);
+
+	return 0;
+}
+
+static int publish_expire(const void *data)
+{
+	struct ast_sip_publication *publication = (struct ast_sip_publication*)data;
+
+	ao2_unlink(publication->handler->publications, publication);
+	publication->sched_id = -1;
+
+	if (ast_sip_push_task(NULL, publish_expire_callback, publication)) {
+		ao2_cleanup(publication);
+	}
+
+	return 0;
+}
+
+static pj_bool_t pubsub_on_rx_publish_request(pjsip_rx_data *rdata)
+{
+	pjsip_event_hdr *event_header;
+	struct ast_sip_publish_handler *handler;
+	RAII_VAR(struct ast_sip_endpoint *, endpoint, NULL, ao2_cleanup);
+	char event[32];
+	static const pj_str_t str_sip_if_match = { "SIP-If-Match", 12 };
+	pjsip_generic_string_hdr *etag_hdr = pjsip_msg_find_hdr_by_name(rdata->msg_info.msg, &str_sip_if_match, NULL);
+	enum sip_publish_type publish_type;
+	RAII_VAR(struct ast_sip_publication *, publication, NULL, ao2_cleanup);
+	int expires = 0, entity_id;
+
+	endpoint = ast_pjsip_rdata_get_endpoint(rdata);
+	ast_assert(endpoint != NULL);
+
+	event_header = pjsip_msg_find_hdr_by_name(rdata->msg_info.msg, &str_event_name, rdata->msg_info.msg->hdr.next);
+	if (!event_header) {
+		ast_log(LOG_WARNING, "Incoming PUBLISH request with no Event header\n");
+		pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 489, NULL, NULL, NULL);
+		return PJ_TRUE;
+	}
+	ast_copy_pj_str(event, &event_header->event_type, sizeof(event));
+
+	handler = find_pub_handler(event);
+	if (!handler) {
+		ast_log(LOG_WARNING, "No registered publish handler for event %s\n", event);
+		pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 489, NULL, NULL, NULL);
+		return PJ_TRUE;
+	}
+
+	publish_type = determine_sip_publish_type(rdata, etag_hdr, &expires, &entity_id);
+
+	/* If this is not an initial publish ensure that a publication is present */
+	if ((publish_type != SIP_PUBLISH_INITIAL) && (publish_type != SIP_PUBLISH_UNKNOWN)) {
+		if (!(publication = ao2_find(handler->publications, &entity_id, OBJ_KEY | OBJ_UNLINK))) {
+			static const pj_str_t str_conditional_request_failed = { "Conditional Request Failed", 26 };
+
+			pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 412, &str_conditional_request_failed,
+				NULL, NULL);
+			return PJ_TRUE;
+		}
+
+		/* Per the RFC every response has to have a new entity tag */
+		publication->entity_tag = ast_atomic_fetchadd_int(&esc_etag_counter, +1);
+
+		/* Update the expires here so that the created responses will contain the correct value */
+		publication->expires = expires;
+	}
+
+	switch (publish_type) {
+		case SIP_PUBLISH_INITIAL:
+			publication = publish_request_initial(endpoint, rdata, handler);
+			break;
+		case SIP_PUBLISH_REFRESH:
+		case SIP_PUBLISH_MODIFY:
+			if (handler->publish_refresh(publication, rdata)) {
+				/* If an error occurs we want to terminate the publication */
+				expires = 0;
+			}
+			break;
+		case SIP_PUBLISH_REMOVE:
+			handler->publish_termination(publication, rdata);
+			break;
+		case SIP_PUBLISH_UNKNOWN:
+		default:
+			pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 400, NULL, NULL, NULL);
+			break;
+	}
+
+	if (publication) {
+		if (expires) {
+			ao2_link(handler->publications, publication);
+
+			AST_SCHED_REPLACE_UNREF(publication->sched_id, sched, expires * 1000, publish_expire, publication,
+				ao2_ref(publication, -1), NULL, ao2_ref(publication, +1));
+		} else {
+			AST_SCHED_DEL_UNREF(sched, publication->sched_id, ao2_ref(publication, -1));
+		}
+	}
+
+	return PJ_TRUE;
+}
+
+/*! \brief Internal destructor for publications */
+static void publication_destroy_fn(void *obj)
+{
+	struct ast_sip_publication *publication = obj;
+
+	ast_debug(3, "Destroying SIP publication\n");
+
+	ao2_cleanup(publication->datastores);
+	ao2_cleanup(publication->endpoint);
+}
+
+struct ast_sip_publication *ast_sip_create_publication(struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata)
+{
+	struct ast_sip_publication *publication;
+	pjsip_expires_hdr *expires_hdr = pjsip_msg_find_hdr(rdata->msg_info.msg, PJSIP_H_EXPIRES, NULL);
+
+	ast_assert(endpoint != NULL);
+
+	if (!(publication = ao2_alloc(sizeof(*publication), publication_destroy_fn))) {
+		return NULL;
+	}
+
+	if (!(publication->datastores = ao2_container_alloc(DATASTORE_BUCKETS, datastore_hash, datastore_cmp))) {
+		ao2_ref(publication, -1);
+		return NULL;
+	}
+
+	publication->entity_tag = ast_atomic_fetchadd_int(&esc_etag_counter, +1);
+	ao2_ref(endpoint, +1);
+	publication->endpoint = endpoint;
+	publication->expires = expires_hdr ? expires_hdr->ivalue : DEFAULT_PUBLISH_EXPIRES;
+	publication->sched_id = -1;
+
+	return publication;
+}
+
+struct ast_sip_endpoint *ast_sip_publication_get_endpoint(struct ast_sip_publication *pub)
+{
+	return pub->endpoint;
+}
+
+int ast_sip_publication_create_response(struct ast_sip_publication *pub, int status_code, pjsip_rx_data *rdata,
+	pjsip_tx_data **tdata)
+{
+	if (pjsip_endpt_create_response(ast_sip_get_pjsip_endpoint(), rdata, status_code, NULL, tdata) != PJ_SUCCESS) {
+		return -1;
+	}
+
+	if (PJSIP_IS_STATUS_IN_CLASS(status_code, 200)) {
+		RAII_VAR(char *, entity_tag, NULL, ast_free_ptr);
+		RAII_VAR(char *, expires, NULL, ast_free_ptr);
+
+		if ((ast_asprintf(&entity_tag, "%d", pub->entity_tag) < 0) ||
+			(ast_asprintf(&expires, "%d", pub->expires) < 0)) {
+			pjsip_tx_data_dec_ref(*tdata);
+			return -1;
+		}
+
+		ast_sip_add_header(*tdata, "SIP-ETag", entity_tag);
+		ast_sip_add_header(*tdata, "Expires", expires);
+	}
+
+	return 0;
+}
+
+pj_status_t ast_sip_publication_send_response(struct ast_sip_publication *pub, pjsip_rx_data *rdata,
+	pjsip_tx_data *tdata)
+{
+	pj_status_t status;
+	pjsip_transaction *tsx;
+
+	if ((status = pjsip_tsx_create_uas(&pubsub_module, rdata, &tsx)) != PJ_SUCCESS) {
+		return status;
+	}
+
+	pjsip_tsx_recv_msg(tsx, rdata);
+
+	return pjsip_tsx_send_msg(tsx, tdata);
+}
+
+static pj_bool_t pubsub_on_rx_request(pjsip_rx_data *rdata)
+{
+	if (!pjsip_method_cmp(&rdata->msg_info.msg->line.req.method, pjsip_get_subscribe_method())) {
+		return pubsub_on_rx_subscribe_request(rdata);
+	} else if (!pjsip_method_cmp(&rdata->msg_info.msg->line.req.method, &pjsip_publish_method)) {
+		return pubsub_on_rx_publish_request(rdata);
+	}
+
+	return PJ_FALSE;
+}
+
 static void pubsub_on_evsub_state(pjsip_evsub *evsub, pjsip_event *event)
 {
 	struct ast_sip_subscription *sub;
@@ -499,7 +934,7 @@ static void pubsub_on_evsub_state(pjsip_evsub *evsub, pjsip_event *event)
 		return;
 	}

-	sub = pjsip_evsub_get_mod_data(evsub, sub_module.id);
+	sub = pjsip_evsub_get_mod_data(evsub, pubsub_module.id);
 	if (!sub) {
 		return;
 	}
@@ -516,12 +951,12 @@ static void pubsub_on_evsub_state(pjsip_evsub *evsub, pjsip_event *event)
 	if (sub->handler->subscription_shutdown) {
 		sub->handler->subscription_shutdown(sub);
 	}
-	pjsip_evsub_set_mod_data(evsub, sub_module.id, NULL);
+	pjsip_evsub_set_mod_data(evsub, pubsub_module.id, NULL);
 }

 static void pubsub_on_tsx_state(pjsip_evsub *evsub, pjsip_transaction *tsx, pjsip_event *event)
 {
-	struct ast_sip_subscription *sub = pjsip_evsub_get_mod_data(evsub, sub_module.id);
+	struct ast_sip_subscription *sub = pjsip_evsub_get_mod_data(evsub, pubsub_module.id);

 	if (!sub) {
 		return;
@@ -548,7 +983,7 @@ static void set_parameters_from_response_data(pj_pool_t *pool, int *p_st_code,
 		struct ast_variable *iter;
 		for (iter = response_data->headers; iter; iter = iter->next) {
 			pj_str_t header_name;
-			pj_str_t header_value;	
+			pj_str_t header_value;
 			pjsip_generic_string_hdr *hdr;

 			pj_cstr(&header_name, iter->name);
@@ -585,7 +1020,7 @@ static int response_data_changed(struct ast_sip_subscription_response_data *resp
 static void pubsub_on_rx_refresh(pjsip_evsub *evsub, pjsip_rx_data *rdata,
 		int *p_st_code, pj_str_t **p_st_text, pjsip_hdr *res_hdr, pjsip_msg_body **p_body)
 {
-	struct ast_sip_subscription *sub = pjsip_evsub_get_mod_data(evsub, sub_module.id);
+	struct ast_sip_subscription *sub = pjsip_evsub_get_mod_data(evsub, pubsub_module.id);
 	struct ast_sip_subscription_response_data response_data = {
 		.status_code = 200,
 	};
@@ -607,7 +1042,7 @@ static void pubsub_on_rx_refresh(pjsip_evsub *evsub, pjsip_rx_data *rdata,
 static void pubsub_on_rx_notify(pjsip_evsub *evsub, pjsip_rx_data *rdata, int *p_st_code,
 		pj_str_t **p_st_text, pjsip_hdr *res_hdr, pjsip_msg_body **p_body)
 {
-	struct ast_sip_subscription *sub = pjsip_evsub_get_mod_data(evsub, sub_module.id);
+	struct ast_sip_subscription *sub = pjsip_evsub_get_mod_data(evsub, pubsub_module.id);
 	struct ast_sip_subscription_response_data response_data = {
 		.status_code = 200,
 	};
@@ -637,7 +1072,7 @@ static int serialized_pubsub_on_client_refresh(void *userdata)

 static void pubsub_on_client_refresh(pjsip_evsub *evsub)
 {
-	struct ast_sip_subscription *sub = pjsip_evsub_get_mod_data(evsub, sub_module.id);
+	struct ast_sip_subscription *sub = pjsip_evsub_get_mod_data(evsub, pubsub_module.id);

 	ao2_ref(sub, +1);
 	ast_sip_push_task(sub->serializer, serialized_pubsub_on_client_refresh, sub);
@@ -654,7 +1089,7 @@ static int serialized_pubsub_on_server_timeout(void *userdata)

 static void pubsub_on_server_timeout(pjsip_evsub *evsub)
 {
-	struct ast_sip_subscription *sub = pjsip_evsub_get_mod_data(evsub, sub_module.id);
+	struct ast_sip_subscription *sub = pjsip_evsub_get_mod_data(evsub, pubsub_module.id);

 	ao2_ref(sub, +1);
 	ast_sip_push_task(sub->serializer, serialized_pubsub_on_server_timeout, sub);
@@ -662,15 +1097,38 @@ static void pubsub_on_server_timeout(pjsip_evsub *evsub)

 static int load_module(void)
 {
+	static const pj_str_t str_PUBLISH = { "PUBLISH", 7 };
+
 	pjsip_evsub_init_module(ast_sip_get_pjsip_endpoint());
-	if (ast_sip_register_service(&sub_module)) {
-		return AST_MODULE_LOAD_DECLINE;
+
+	if (!(sched = ast_sched_context_create())) {
+		ast_log(LOG_ERROR, "Could not create scheduler for publication expiration\n");
+		return AST_MODULE_LOAD_FAILURE;
 	}
+
+	if (ast_sched_start_thread(sched)) {
+		ast_log(LOG_ERROR, "Could not start scheduler thread for publication expiration\n");
+		ast_sched_context_destroy(sched);
+		return AST_MODULE_LOAD_FAILURE;
+	}
+
+	pjsip_endpt_add_capability(ast_sip_get_pjsip_endpoint(), NULL, PJSIP_H_ALLOW, NULL, 1, &str_PUBLISH);
+
+	if (ast_sip_register_service(&pubsub_module)) {
+		ast_log(LOG_ERROR, "Could not register pubsub service\n");
+		ast_sched_context_destroy(sched);
+		return AST_MODULE_LOAD_FAILURE;
+	}
+
 	return AST_MODULE_LOAD_SUCCESS;
 }

 static int unload_module(void)
 {
+	if (sched) {
+		ast_sched_context_destroy(sched);
+	}
+
 	return 0;
 }

--- a/res/res_sip_pubsub.exports.in
+++ b/res/res_sip_pubsub.exports.in
@@ -12,6 +12,15 @@
 		LINKER_SYMBOL_PREFIXast_sip_subscription_remove_datastore;
 		LINKER_SYMBOL_PREFIXast_sip_register_subscription_handler;
 		LINKER_SYMBOL_PREFIXast_sip_unregister_subscription_handler;
+		LINKER_SYMBOL_PREFIXast_sip_create_publication;
+		LINKER_SYMBOL_PREFIXast_sip_publication_get_endpoint;
+		LINKER_SYMBOL_PREFIXast_sip_publication_create_response;
+		LINKER_SYMBOL_PREFIXast_sip_publication_send_response;
+		LINKER_SYMBOL_PREFIXast_sip_register_publish_handler;
+		LINKER_SYMBOL_PREFIXast_sip_unregister_publish_handler;
+		LINKER_SYMBOL_PREFIXast_sip_publication_add_datastore;
+		LINKER_SYMBOL_PREFIXast_sip_publication_get_datastore;
+		LINKER_SYMBOL_PREFIXast_sip_publication_remove_datastore;
 	local:
 		*;
 };