evsub.c

一个开源SIP协议栈

/* $Id: evsub.c 974 2007-02-19 01:13:53Z bennylp $ */
/* 
 * Copyright (C) 2003-2007 Benny Prijono <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
 */
#include <pjsip-simple/evsub.h>
#include <pjsip-simple/evsub_msg.h>
#include <pjsip-simple/errno.h>
#include <pjsip/sip_errno.h>
#include <pjsip/sip_module.h>
#include <pjsip/sip_endpoint.h>
#include <pjsip/sip_dialog.h>
#include <pjsip/sip_auth.h>
#include <pjsip/sip_transaction.h>
#include <pjsip/sip_event.h>
#include <pj/assert.h>
#include <pj/guid.h>
#include <pj/log.h>
#include <pj/os.h>
#include <pj/pool.h>
#include <pj/string.h>


#define THIS_FILE	"evsub.c"

/*
 * Global constant
 */

/* Let's define this enum, so that it'll trigger compilation error
 * when somebody define the same enum in sip_msg.h
 */
enum
{
    PJSIP_SUBSCRIBE_METHOD = PJSIP_OTHER_METHOD,
    PJSIP_NOTIFY_METHOD = PJSIP_OTHER_METHOD
};

const pjsip_method pjsip_subscribe_method = 
{
    PJSIP_SUBSCRIBE_METHOD,
    { "SUBSCRIBE", 9 }
};

const pjsip_method pjsip_notify_method = 
{
    PJSIP_NOTIFY_METHOD,
    { "NOTIFY", 6 }
};

/*
 * Static prototypes.
 */
static void	   mod_evsub_on_tsx_state(pjsip_transaction*, pjsip_event*);
static pj_status_t mod_evsub_unload(void);


/*
 * State names.
 */
static pj_str_t evsub_state_names[] = 
{
    { "NULL",	    4},
    { "SENT",	    4},
    { "ACCEPTED",   8},
    { "PENDING",    7},
    { "ACTIVE",	    6},
    { "TERMINATED", 10},
    { "UNKNOWN",    7}
};

/*
 * Timer constants.
 */

/* Number of seconds to send SUBSCRIBE before the actual expiration */
#define TIME_UAC_REFRESH	5

/* Time to wait for the final NOTIFY after sending unsubscription */
#define TIME_UAC_TERMINATE	5

/* If client responds NOTIFY with non-2xx final response (such as 401),
 * wait for this seconds for further NOTIFY, otherwise client will
 * unsubscribe
 */
#define TIME_UAC_WAIT_NOTIFY	5


/*
 * Timer id
 */
enum timer_id
{
    /* No timer. */
    TIMER_TYPE_NONE,

    /* Time to refresh client subscription. 
     * The action is to call on_client_refresh() callback.
     */
    TIMER_TYPE_UAC_REFRESH,

    /* UAS timeout after to subscription refresh. 
     * The action is to call on_server_timeout() callback.
     */
    TIMER_TYPE_UAS_TIMEOUT,

    /* UAC waiting for final NOTIFY after unsubscribing 
     * The action is to terminate.
     */
    TIMER_TYPE_UAC_TERMINATE,

    /* UAC waiting for further NOTIFY after sending non-2xx response to 
     * NOTIFY. The action is to unsubscribe.
     */
    TIMER_TYPE_UAC_WAIT_NOTIFY,

    /* Max nb of timer types. */
    TIMER_TYPE_MAX
};

static const char *timer_names[] = 
{
    "None",
    "UAC_REFRESH",
    "UAS_TIMEOUT"
    "UAC_TERMINATE",
    "UAC_WAIT_NOTIFY",
    "INVALID_TIMER"
};

/*
 * Definition of event package.
 */
struct evpkg
{
    PJ_DECL_LIST_MEMBER(struct evpkg);

    pj_str_t		 pkg_name;
    pjsip_module	*pkg_mod;
    unsigned		 pkg_expires;
    pjsip_accept_hdr	*pkg_accept;
};


/*
 * Event subscription module (mod-evsub).
 */
static struct mod_evsub
{
    pjsip_module	     mod;
    pj_pool_t		    *pool;
    pjsip_endpoint	    *endpt;
    struct evpkg	     pkg_list;
    pjsip_allow_events_hdr  *allow_events_hdr;

} mod_evsub = 
{
    {
	NULL, NULL,			    /* prev, next.		*/
	{ "mod-evsub", 9 },		    /* Name.			*/
	-1,				    /* Id			*/
	PJSIP_MOD_PRIORITY_DIALOG_USAGE,    /* Priority			*/
	NULL,				    /* load()			*/
	NULL,				    /* start()			*/
	NULL,				    /* stop()			*/
	&mod_evsub_unload,		    /* unload()			*/
	NULL,				    /* on_rx_request()		*/
	NULL,				    /* on_rx_response()		*/
	NULL,				    /* on_tx_request.		*/
	NULL,				    /* on_tx_response()		*/
	&mod_evsub_on_tsx_state,	    /* on_tsx_state()		*/
    }
};


/*
 * Event subscription session.
 */
struct pjsip_evsub
{
    char		  obj_name[PJ_MAX_OBJ_NAME]; /**< Name.		    */
    pj_pool_t		 *pool;		/**< Pool.			    */
    pjsip_endpoint	 *endpt;	/**< Endpoint instance.		    */
    pjsip_dialog	 *dlg;		/**< Underlying dialog.		    */
    struct evpkg	 *pkg;		/**< The event package.		    */
    unsigned		  option;	/**< Options.			    */
    pjsip_evsub_user	  user;		/**< Callback.			    */
    pj_bool_t		  call_cb;	/**< Notify callback?		    */
    pjsip_role_e	  role;		/**< UAC=subscriber, UAS=notifier   */
    pjsip_evsub_state	  state;	/**< Subscription state.	    */
    pj_str_t		  state_str;	/**< String describing the state.   */
    pjsip_evsub_state	  dst_state;	/**< Pending state to be set.	    */
    pj_str_t		  dst_state_str;/**< Pending state to be set.	    */
    pjsip_method	  method;	/**< Method that established subscr.*/
    pjsip_event_hdr	 *event;	/**< Event description.		    */
    pjsip_expires_hdr	 *expires;	/**< Expires header		    */
    pjsip_accept_hdr	 *accept;	/**< Local Accept header.	    */

    pj_time_val		  refresh_time;	/**< Time to refresh.		    */
    pj_timer_entry	  timer;	/**< Internal timer.		    */
    int			  pending_tsx;	/**< Number of pending transactions.*/
    pjsip_transaction	 *pending_sub;	/**< Pending UAC SUBSCRIBE tsx.	    */

    void		 *mod_data[PJSIP_MAX_MODULE];	/**< Module data.   */
};


/*
 * This is the structure that will be "attached" to dialog.
 * The purpose is to allow multiple subscriptions inside a dialog.
 */
struct dlgsub
{
    PJ_DECL_LIST_MEMBER(struct dlgsub);
    pjsip_evsub *sub;
};


/* Static vars. */
static const pj_str_t STR_EVENT	     = { "Event", 5 };
static const pj_str_t STR_SUB_STATE  = { "Subscription-State", 18 };
static const pj_str_t STR_TERMINATED = { "terminated", 10 };
static const pj_str_t STR_ACTIVE     = { "active", 6 };
static const pj_str_t STR_PENDING    = { "pending", 7 };
static const pj_str_t STR_TIMEOUT    = { "timeout", 7};


/*
 * On unload module.
 */
static pj_status_t mod_evsub_unload(void)
{
    pjsip_endpt_release_pool(mod_evsub.endpt, mod_evsub.pool);
    mod_evsub.pool = NULL;

    return PJ_SUCCESS;
}

/* Proto for pjsipsimple_strerror().
 * Defined in errno.c
 */
PJ_DECL(pj_str_t) pjsipsimple_strerror( pj_status_t statcode, 
				        char *buf, pj_size_t bufsize );

/*
 * Init and register module.
 */
PJ_DEF(pj_status_t) pjsip_evsub_init_module(pjsip_endpoint *endpt)
{
    pj_status_t status;
    pj_str_t method_tags[] = {
	{ "SUBSCRIBE", 9},
	{ "NOTIFY", 6}
    };

    pj_register_strerror(PJSIP_SIMPLE_ERRNO_START, PJ_ERRNO_SPACE_SIZE,
			 &pjsipsimple_strerror);

    PJ_ASSERT_RETURN(endpt != NULL, PJ_EINVAL);
    PJ_ASSERT_RETURN(mod_evsub.mod.id == -1, PJ_EINVALIDOP);

    /* Keep endpoint for future reference: */
    mod_evsub.endpt = endpt;

    /* Init event package list: */
    pj_list_init(&mod_evsub.pkg_list);

    /* Create pool: */
    mod_evsub.pool = pjsip_endpt_create_pool(endpt, "evsub", 4000, 4000);
    if (!mod_evsub.pool)
	return PJ_ENOMEM;

    /* Register module: */
    status = pjsip_endpt_register_module(endpt, &mod_evsub.mod);
    if (status  != PJ_SUCCESS)
	goto on_error;
 
    /* Create Allow-Events header: */
    mod_evsub.allow_events_hdr = pjsip_allow_events_hdr_create(mod_evsub.pool);

    /* Register SIP-event specific headers parser: */
    pjsip_evsub_init_parser();

    /* Register new methods SUBSCRIBE and NOTIFY in Allow-ed header */
    pjsip_endpt_add_capability(endpt, &mod_evsub.mod, PJSIP_H_ALLOW, NULL,
			       2, method_tags);

    /* Done. */
    return PJ_SUCCESS;

on_error:
    if (mod_evsub.pool) {
	pjsip_endpt_release_pool(endpt, mod_evsub.pool);
	mod_evsub.pool = NULL;
    }
    mod_evsub.endpt = NULL;
    return status;
}


/*
 * Get the instance of the module.
 */
PJ_DEF(pjsip_module*) pjsip_evsub_instance(void)
{
    PJ_ASSERT_RETURN(mod_evsub.mod.id != -1, NULL);

    return &mod_evsub.mod;
}


/*
 * Get the event subscription instance in the transaction.
 */
PJ_DEF(pjsip_evsub*) pjsip_tsx_get_evsub(pjsip_transaction *tsx)
{
    return tsx->mod_data[mod_evsub.mod.id];
}


/*
 * Set event subscription's module data.
 */
PJ_DEF(void) pjsip_evsub_set_mod_data( pjsip_evsub *sub, unsigned mod_id,
				       void *data )
{
    PJ_ASSERT_ON_FAIL(mod_id < PJSIP_MAX_MODULE, return);
    sub->mod_data[mod_id] = data;
}


/*
 * Get event subscription's module data.
 */
PJ_DEF(void*) pjsip_evsub_get_mod_data( pjsip_evsub *sub, unsigned mod_id )
{
    PJ_ASSERT_RETURN(mod_id < PJSIP_MAX_MODULE, NULL);
    return sub->mod_data[mod_id];
}


/*
 * Find registered event package with matching name.
 */
static struct evpkg* find_pkg(const pj_str_t *event_name)
{
    struct evpkg *pkg;

    pkg = mod_evsub.pkg_list.next;
    while (pkg != &mod_evsub.pkg_list) {

	if (pj_stricmp(&pkg->pkg_name, event_name) == 0) {
	    return pkg;
	}

	pkg = pkg->next;
    }

    return NULL;
}

/*
 * Register an event package
 */
PJ_DEF(pj_status_t) pjsip_evsub_register_pkg( pjsip_module *pkg_mod,
					      const pj_str_t *event_name,
					      unsigned expires,
					      unsigned accept_cnt,
					      const pj_str_t accept[])
{
    struct evpkg *pkg;
    unsigned i;

    PJ_ASSERT_RETURN(pkg_mod && event_name, PJ_EINVAL);
    PJ_ASSERT_RETURN(accept_cnt < PJ_ARRAY_SIZE(pkg->pkg_accept->values), 
		     PJ_ETOOMANY);

    /* Make sure no module with the specified name already registered: */

    PJ_ASSERT_RETURN(find_pkg(event_name) == NULL, PJSIP_SIMPLE_EPKGEXISTS);


    /* Create new event package: */

    pkg = pj_pool_alloc(mod_evsub.pool, sizeof(struct evpkg));
    pkg->pkg_mod = pkg_mod;
    pkg->pkg_expires = expires;
    pj_strdup(mod_evsub.pool, &pkg->pkg_name, event_name);

    pkg->pkg_accept = pjsip_accept_hdr_create(mod_evsub.pool);
    pkg->pkg_accept->count = accept_cnt;
    for (i=0; i<accept_cnt; ++i) {
	pj_strdup(mod_evsub.pool, &pkg->pkg_accept->values[i], &accept[i]);
    }

    /* Add to package list: */

    pj_list_push_back(&mod_evsub.pkg_list, pkg);

    /* Add to Allow-Events header: */

    if (mod_evsub.allow_events_hdr->count !=
	PJ_ARRAY_SIZE(mod_evsub.allow_events_hdr->values))
    {
	mod_evsub.allow_events_hdr->values[mod_evsub.allow_events_hdr->count] =
	    pkg->pkg_name;
	++mod_evsub.allow_events_hdr->count;
    }
    
    /* Add to endpoint's Accept header */
    pjsip_endpt_add_capability(mod_evsub.endpt, &mod_evsub.mod,
			       PJSIP_H_ACCEPT, NULL,
			       pkg->pkg_accept->count,
			       pkg->pkg_accept->values);


    /* Done */

    PJ_LOG(5,(THIS_FILE, "Event pkg \"%.*s\" registered by %.*s",
	      (int)event_name->slen, event_name->ptr,
	      (int)pkg_mod->name.slen, pkg_mod->name.ptr));

    return PJ_SUCCESS;
}


/*
 * Retrieve Allow-Events header
 */
PJ_DEF(const pjsip_hdr*) pjsip_evsub_get_allow_events_hdr(pjsip_module *m)
{
    struct mod_evsub *mod;

    if (m == NULL)
	m = pjsip_evsub_instance();

    mod = (struct mod_evsub*)m;

    return (pjsip_hdr*) mod->allow_events_hdr;
}


/*
 * Update expiration time.
 */
static void update_expires( pjsip_evsub *sub, pj_uint32_t interval )
{
    pj_gettimeofday(&sub->refresh_time);
    sub->refresh_time.sec += interval;
}


/* 
 * Schedule timer.
 */
static void set_timer( pjsip_evsub *sub, int timer_id,
		       pj_int32_t seconds)
{
    if (sub->timer.id != TIMER_TYPE_NONE) {
	PJ_LOG(5,(sub->obj_name, "%s %s timer", 
		  (timer_id==sub->timer.id ? "Updating" : "Cancelling"),
		  timer_names[sub->timer.id]));
	pjsip_endpt_cancel_timer(sub->endpt, &sub->timer);
	sub->timer.id = TIMER_TYPE_NONE;
    }

    if (timer_id != TIMER_TYPE_NONE) {
	pj_time_val timeout;

	PJ_ASSERT_ON_FAIL(seconds > 0, return);
	PJ_ASSERT_ON_FAIL(timer_id>TIMER_TYPE_NONE && timer_id<TIMER_TYPE_MAX,
			  return);

	timeout.sec = seconds;
	timeout.msec = 0;
	sub->timer.id = timer_id;

	pjsip_endpt_schedule_timer(sub->endpt, &sub->timer, &timeout);

	PJ_LOG(5,(sub->obj_name, "Timer %s scheduled in %d seconds", 
		  timer_names[sub->timer.id], timeout.sec));
    }
}