libsmb/trustdom_cache.c

Implementation of trusted domain names cache useful when samba acts as domain member server. [詳細]

ソースコードを見る。

関数
BOOL	trustdom_cache_enable (void)
	Initialise trustdom name caching system.
BOOL	trustdom_cache_shutdown (void)
	Shutdown trustdom name caching system.
static char *	trustdom_cache_key (const char *name)
	Form up trustdom name key.
BOOL	trustdom_cache_store (char *name, char *alt_name, const DOM_SID *sid, time_t timeout)
	Store trusted domain in gencache as the domain name (key) and ip address of domain controller (value)
BOOL	trustdom_cache_fetch (const char *name, DOM_SID *sid)
	Fetch trusted domain's dc from the gencache.
uint32	trustdom_cache_fetch_timestamp (void)
BOOL	trustdom_cache_store_timestamp (uint32 t, time_t timeout)
static void	flush_trustdom_name (const char *key, const char *value, time_t timeout, void *dptr)
	Delete single trustdom entry.
void	trustdom_cache_flush (void)
	Flush all the trusted domains entries from the cache.
void	update_trustdom_cache (void)

---

説明

Implementation of trusted domain names cache useful when samba acts as domain member server.

In such case, caching domain names currently trusted gives a performance gain because there's no need to query PDC each time we need list of trusted domains

trustdom_cache.c で定義されています。

---

関数

BOOL trustdom_cache_enable

(

void

)

Initialise trustdom name caching system.

Call gencache initialisation routine to perform necessary activities.

戻り値:

true upon successful cache initialisation or false if cache init failed

trustdom_cache.c の 51 行で定義されています。

参照先 gencache_init().

{
        /* Init trustdom cache by calling gencache initialisation */
        if (!gencache_init()) {
                DEBUG(2, ("trustdomcache_enable: Couldn't initialise trustdom cache on top of gencache.\n"));
                return False;
        }

        return True;
}

BOOL trustdom_cache_shutdown

(

void

)

Shutdown trustdom name caching system.

Calls gencache shutdown function.

戻り値:

true upon successful cache close or false if it failed

trustdom_cache.c の 71 行で定義されています。

参照先 gencache_shutdown().

参照元 terminate().

{
        /* Close trustdom cache by calling gencache shutdown */
        if (!gencache_shutdown()) {
                DEBUG(2, ("trustdomcache_shutdown: Couldn't shutdown trustdom cache on top of gencache.\n"));
                return False;
        }
        
        return True;
}

static char* trustdom_cache_key

(

const char *

name

)

[static]

Form up trustdom name key.

It is based only on domain name now.

引数:

name

trusted domain name

戻り値:

cache key for use in gencache mechanism

trustdom_cache.c の 91 行で定義されています。

参照先 asprintf()・strupper_static().

参照元 trustdom_cache_fetch()・trustdom_cache_flush()・trustdom_cache_store().

{
        char* keystr = NULL;
        asprintf(&keystr, TDOMKEY_FMT, strupper_static(name));
        
        return keystr;
}

BOOL trustdom_cache_store	(	char *	name,
		char *	alt_name,
		const DOM_SID *	sid,
		time_t	timeout
	)

Store trusted domain in gencache as the domain name (key) and ip address of domain controller (value)

引数:

	name	trusted domain name
	alt_name	alternative trusted domain name (used in ADS domains)
	sid	trusted domain's SID
	timeout	cache entry expiration time

戻り値:

true upon successful value storing or false if store attempt failed

trustdom_cache.c の 112 行で定義されています。

参照先 gencache_init()・gencache_set()・sid_string_static()・sid_to_string()・trustdom_cache_key().

参照元 update_trustdom_cache().

{
        char *key, *alt_key;
        fstring sid_string;
        BOOL ret;

        /*
         * we use gecache call to avoid annoying debug messages
         * about initialised trustdom 
         */
        if (!gencache_init())
                return False;

        DEBUG(5, ("trustdom_store: storing SID %s of domain %s\n",
                  sid_string_static(sid), name));

        key = trustdom_cache_key(name);
        alt_key = alt_name ? trustdom_cache_key(alt_name) : NULL;

        /* Generate string representation domain SID */
        sid_to_string(sid_string, sid);

        /*
         * try to put the names in the cache
         */
        if (alt_key) {
                ret = gencache_set(alt_key, sid_string, timeout);
                if ( ret ) {
                        ret = gencache_set(key, sid_string, timeout);
                }
                SAFE_FREE(alt_key);
                SAFE_FREE(key);
                return ret;
        }

        ret = gencache_set(key, sid_string, timeout);
        SAFE_FREE(key);
        return ret;
}

BOOL trustdom_cache_fetch	(	const char *	name,
		DOM_SID *	sid
	)

Fetch trusted domain's dc from the gencache.

This routine can also be used to check whether given domain is currently trusted one.

引数:

	name	trusted domain name
	sid	trusted domain's SID to be returned

戻り値:

true if entry is found or false if has expired/doesn't exist

trustdom_cache.c の 165 行で定義されています。

参照先 gencache_get()・gencache_init()・string_to_sid()・timeout・trustdom_cache_key().

参照元 is_trusted_domain().

{
        char *key = NULL, *value = NULL;
        time_t timeout;

        /* init the cache */
        if (!gencache_init())
                return False;
        
        /* exit now if null pointers were passed as they're required further */
        if (!sid)
                return False;

        /* prepare a key and get the value */
        key = trustdom_cache_key(name);
        if (!key)
                return False;
        
        if (!gencache_get(key, &value, &timeout)) {
                DEBUG(5, ("no entry for trusted domain %s found.\n", name));
                SAFE_FREE(key);
                return False;
        } else {
                SAFE_FREE(key);
                DEBUG(5, ("trusted domain %s found (%s)\n", name, value));
        }

        /* convert ip string representation into in_addr structure */
        if(! string_to_sid(sid, value)) {
                sid = NULL;
                SAFE_FREE(value);
                return False;
        }
        
        SAFE_FREE(value);
        return True;
}

uint32 trustdom_cache_fetch_timestamp

(

void

)

trustdom_cache.c の 208 行で定義されています。

参照先 gencache_get()・gencache_init()・timeout.

参照元 update_trustdom_cache().

{
        char *value = NULL;
        time_t timeout;
        uint32 timestamp;

        /* init the cache */
        if (!gencache_init()) 
                return False;
                
        if (!gencache_get(TDOMTSKEY, &value, &timeout)) {
                DEBUG(5, ("no timestamp for trusted domain cache located.\n"));
                SAFE_FREE(value);
                return 0;
        } 

        timestamp = atoi(value);
                
        SAFE_FREE(value);
        return timestamp;
}

BOOL trustdom_cache_store_timestamp	(	uint32	t,
		time_t	timeout
	)

trustdom_cache.c の 234 行で定義されています。

参照先 fstr_sprintf()・gencache_init()・gencache_set().

参照元 update_trustdom_cache().

{
        fstring value;

        /* init the cache */
        if (!gencache_init()) 
                return False;
                
        fstr_sprintf(value, "%d", t );
                
        if (!gencache_set(TDOMTSKEY, value, timeout)) {
                DEBUG(5, ("failed to set timestamp for trustdom_cache\n"));
                return False;
        } 

        return True;
}

static void flush_trustdom_name	(	const char *	key,
		const char *	value,
		time_t	timeout,
		void *	dptr
	)			[static]

Delete single trustdom entry.

Look at the gencache_iterate definition.

trustdom_cache.c の 259 行で定義されています。

参照先 gencache_del().

参照元 trustdom_cache_flush().

{
        gencache_del(key);
        DEBUG(5, ("Deleting entry %s\n", key));
}

void trustdom_cache_flush

(

void

)

Flush all the trusted domains entries from the cache.

trustdom_cache.c の 270 行で定義されています。

参照先 flush_trustdom_name()・gencache_init()・gencache_iterate()・trustdom_cache_key().

{
        if (!gencache_init())
                return;

        /* 
         * iterate through each TDOM cache's entry and flush it
         * by flush_trustdom_name function
         */
        gencache_iterate(flush_trustdom_name, NULL, trustdom_cache_key("*"));
        DEBUG(5, ("Trusted domains cache flushed\n"));
}

void update_trustdom_cache

(

void

)

trustdom_cache.c の 288 行で定義されています。

参照先 enumerate_domain_trusts()・lp_workgroup()・num_domains・talloc_init()・trustdom_cache_fetch_timestamp()・trustdom_cache_store()・trustdom_cache_store_timestamp().

参照元 is_trusted_domain().

{
        char **domain_names;
        DOM_SID *dom_sids;
        uint32 num_domains;
        uint32 last_check;
        int time_diff;
        TALLOC_CTX *mem_ctx = NULL;
        time_t now = time(NULL);
        int i;
        
        /* get the timestamp.  We have to initialise it if the last timestamp == 0 */   
        if ( (last_check = trustdom_cache_fetch_timestamp()) == 0 ) 
                trustdom_cache_store_timestamp(0, now+TRUSTDOM_UPDATE_INTERVAL);

        time_diff = (int) (now - last_check);
        
        if ( (time_diff > 0) && (time_diff < TRUSTDOM_UPDATE_INTERVAL) ) {
                DEBUG(10,("update_trustdom_cache: not time to update trustdom_cache yet\n"));
                return;
        }

        /* note that we don't lock the timestamp. This prevents this
           smbd from blocking all other smbd daemons while we
           enumerate the trusted domains */
        trustdom_cache_store_timestamp(now, now+TRUSTDOM_UPDATE_INTERVAL);
                
        if ( !(mem_ctx = talloc_init("update_trustdom_cache")) ) {
                DEBUG(0,("update_trustdom_cache: talloc_init() failed!\n"));
                goto done;
        }

        /* get the domains and store them */
        
        if ( enumerate_domain_trusts(mem_ctx, lp_workgroup(), &domain_names, 
                &num_domains, &dom_sids)) {
                for ( i=0; i<num_domains; i++ ) {
                        trustdom_cache_store( domain_names[i], NULL, &dom_sids[i], 
                                now+TRUSTDOM_UPDATE_INTERVAL);
                }               
        } else {
                /* we failed to fetch the list of trusted domains - restore the old
                   timestamp */
                trustdom_cache_store_timestamp(last_check, 
                                               last_check+TRUSTDOM_UPDATE_INTERVAL);
        }

done:   
        talloc_destroy( mem_ctx );
        
        return;
}

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