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DEFINITIONS
This source file includes following definitions.
- ssl_scache_dbm_init
- ssl_scache_dbm_kill
- ssl_scache_dbm_store
- ssl_scache_dbm_retrieve
- ssl_scache_dbm_remove
- ssl_scache_dbm_expire
- ssl_scache_dbm_status
/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* _ _
* _ __ ___ ___ __| | ___ ___| | mod_ssl
* | '_ ` _ \ / _ \ / _` | / __/ __| | Apache Interface to OpenSSL
* | | | | | | (_) | (_| | \__ \__ \ |
* |_| |_| |_|\___/ \__,_|___|___/___/_|
* |_____|
* ssl_scache_dbm.c
* Session Cache via DBM
*/
#include "ssl_private.h"
static void ssl_scache_dbm_expire(server_rec *s);
void ssl_scache_dbm_init(server_rec *s, apr_pool_t *p)
{
SSLModConfigRec *mc = myModConfig(s);
apr_dbm_t *dbm;
apr_status_t rv;
/* for the DBM we need the data file */
if (mc->szSessionCacheDataFile == NULL) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
"SSLSessionCache required");
ssl_die();
}
/* open it once to create it and to make sure it _can_ be created */
ssl_mutex_on(s);
if ((rv = apr_dbm_open(&dbm, mc->szSessionCacheDataFile,
APR_DBM_RWCREATE, SSL_DBM_FILE_MODE, mc->pPool)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, s,
"Cannot create SSLSessionCache DBM file `%s'",
mc->szSessionCacheDataFile);
ssl_mutex_off(s);
return;
}
apr_dbm_close(dbm);
#if !defined(OS2) && !defined(WIN32) && !defined(BEOS) && !defined(NETWARE)
/*
* We have to make sure the Apache child processes have access to
* the DBM file. But because there are brain-dead platforms where we
* cannot exactly determine the suffixes we try all possibilities.
*/
if (geteuid() == 0 /* is superuser */) {
chown(mc->szSessionCacheDataFile, unixd_config.user_id, -1 /* no gid change */);
if (chown(apr_pstrcat(p, mc->szSessionCacheDataFile, SSL_DBM_FILE_SUFFIX_DIR, NULL),
unixd_config.user_id, -1) == -1) {
if (chown(apr_pstrcat(p, mc->szSessionCacheDataFile, ".db", NULL),
unixd_config.user_id, -1) == -1)
chown(apr_pstrcat(p, mc->szSessionCacheDataFile, ".dir", NULL),
unixd_config.user_id, -1);
}
if (chown(apr_pstrcat(p, mc->szSessionCacheDataFile, SSL_DBM_FILE_SUFFIX_PAG, NULL),
unixd_config.user_id, -1) == -1) {
if (chown(apr_pstrcat(p, mc->szSessionCacheDataFile, ".db", NULL),
unixd_config.user_id, -1) == -1)
chown(apr_pstrcat(p, mc->szSessionCacheDataFile, ".pag", NULL),
unixd_config.user_id, -1);
}
}
#endif
ssl_mutex_off(s);
ssl_scache_dbm_expire(s);
return;
}
void ssl_scache_dbm_kill(server_rec *s)
{
SSLModConfigRec *mc = myModConfig(s);
apr_pool_t *p;
apr_pool_create_ex(&p, mc->pPool, NULL, NULL);
if (p != NULL) {
/* the correct way */
unlink(apr_pstrcat(p, mc->szSessionCacheDataFile, SSL_DBM_FILE_SUFFIX_DIR, NULL));
unlink(apr_pstrcat(p, mc->szSessionCacheDataFile, SSL_DBM_FILE_SUFFIX_PAG, NULL));
/* the additional ways to be sure */
unlink(apr_pstrcat(p, mc->szSessionCacheDataFile, ".dir", NULL));
unlink(apr_pstrcat(p, mc->szSessionCacheDataFile, ".pag", NULL));
unlink(apr_pstrcat(p, mc->szSessionCacheDataFile, ".db", NULL));
unlink(mc->szSessionCacheDataFile);
apr_pool_destroy(p);
}
return;
}
BOOL ssl_scache_dbm_store(server_rec *s, UCHAR *id, int idlen, time_t expiry, SSL_SESSION *sess)
{
SSLModConfigRec *mc = myModConfig(s);
apr_dbm_t *dbm;
apr_datum_t dbmkey;
apr_datum_t dbmval;
UCHAR ucaData[SSL_SESSION_MAX_DER];
int nData;
UCHAR *ucp;
apr_status_t rv;
/* streamline session data */
if ((nData = i2d_SSL_SESSION(sess, NULL)) > sizeof(ucaData)) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
"streamline session data size too large: %d > "
"%" APR_SIZE_T_FMT,
nData, sizeof(ucaData));
return FALSE;
}
ucp = ucaData;
i2d_SSL_SESSION(sess, &ucp);
/* be careful: do not try to store too much bytes in a DBM file! */
#ifdef PAIRMAX
if ((idlen + nData) >= PAIRMAX) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
"data size too large for DBM session cache: %d >= %d",
(idlen + nData), PAIRMAX);
return FALSE;
}
#else
if ((idlen + nData) >= 950 /* at least less than approx. 1KB */) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
"data size too large for DBM session cache: %d >= %d",
(idlen + nData), 950);
return FALSE;
}
#endif
/* create DBM key */
dbmkey.dptr = (char *)id;
dbmkey.dsize = idlen;
/* create DBM value */
dbmval.dsize = sizeof(time_t) + nData;
dbmval.dptr = (char *)malloc(dbmval.dsize);
if (dbmval.dptr == NULL) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
"malloc error creating DBM value");
return FALSE;
}
memcpy((char *)dbmval.dptr, &expiry, sizeof(time_t));
memcpy((char *)dbmval.dptr+sizeof(time_t), ucaData, nData);
/* and store it to the DBM file */
ssl_mutex_on(s);
if ((rv = apr_dbm_open(&dbm, mc->szSessionCacheDataFile,
APR_DBM_RWCREATE, SSL_DBM_FILE_MODE, mc->pPool)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, s,
"Cannot open SSLSessionCache DBM file `%s' for writing "
"(store)",
mc->szSessionCacheDataFile);
ssl_mutex_off(s);
free(dbmval.dptr);
return FALSE;
}
if ((rv = apr_dbm_store(dbm, dbmkey, dbmval)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, s,
"Cannot store SSL session to DBM file `%s'",
mc->szSessionCacheDataFile);
apr_dbm_close(dbm);
ssl_mutex_off(s);
free(dbmval.dptr);
return FALSE;
}
apr_dbm_close(dbm);
ssl_mutex_off(s);
/* free temporary buffers */
free(dbmval.dptr);
/* allow the regular expiring to occur */
ssl_scache_dbm_expire(s);
return TRUE;
}
SSL_SESSION *ssl_scache_dbm_retrieve(server_rec *s, UCHAR *id, int idlen)
{
SSLModConfigRec *mc = myModConfig(s);
apr_dbm_t *dbm;
apr_datum_t dbmkey;
apr_datum_t dbmval;
SSL_SESSION *sess = NULL;
MODSSL_D2I_SSL_SESSION_CONST unsigned char *ucpData;
int nData;
time_t expiry;
time_t now;
apr_status_t rc;
/* allow the regular expiring to occur */
ssl_scache_dbm_expire(s);
/* create DBM key and values */
dbmkey.dptr = (char *)id;
dbmkey.dsize = idlen;
/* and fetch it from the DBM file
* XXX: Should we open the dbm against r->pool so the cleanup will
* do the apr_dbm_close? This would make the code a bit cleaner.
*/
ssl_mutex_on(s);
if ((rc = apr_dbm_open(&dbm, mc->szSessionCacheDataFile,
APR_DBM_RWCREATE, SSL_DBM_FILE_MODE, mc->pPool)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rc, s,
"Cannot open SSLSessionCache DBM file `%s' for reading "
"(fetch)",
mc->szSessionCacheDataFile);
ssl_mutex_off(s);
return NULL;
}
rc = apr_dbm_fetch(dbm, dbmkey, &dbmval);
if (rc != APR_SUCCESS) {
apr_dbm_close(dbm);
ssl_mutex_off(s);
return NULL;
}
if (dbmval.dptr == NULL || dbmval.dsize <= sizeof(time_t)) {
apr_dbm_close(dbm);
ssl_mutex_off(s);
return NULL;
}
/* parse resulting data */
nData = dbmval.dsize-sizeof(time_t);
ucpData = malloc(nData);
if (ucpData == NULL) {
apr_dbm_close(dbm);
ssl_mutex_off(s);
return NULL;
}
/* Cast needed, ucpData may be const */
memcpy((unsigned char *)ucpData,
(char *)dbmval.dptr + sizeof(time_t), nData);
memcpy(&expiry, dbmval.dptr, sizeof(time_t));
apr_dbm_close(dbm);
ssl_mutex_off(s);
/* make sure the stuff is still not expired */
now = time(NULL);
if (expiry <= now) {
ssl_scache_dbm_remove(s, id, idlen);
return NULL;
}
/* unstreamed SSL_SESSION */
sess = d2i_SSL_SESSION(NULL, &ucpData, nData);
return sess;
}
void ssl_scache_dbm_remove(server_rec *s, UCHAR *id, int idlen)
{
SSLModConfigRec *mc = myModConfig(s);
apr_dbm_t *dbm;
apr_datum_t dbmkey;
apr_status_t rv;
/* create DBM key and values */
dbmkey.dptr = (char *)id;
dbmkey.dsize = idlen;
/* and delete it from the DBM file */
ssl_mutex_on(s);
if ((rv = apr_dbm_open(&dbm, mc->szSessionCacheDataFile,
APR_DBM_RWCREATE, SSL_DBM_FILE_MODE, mc->pPool)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, s,
"Cannot open SSLSessionCache DBM file `%s' for writing "
"(delete)",
mc->szSessionCacheDataFile);
ssl_mutex_off(s);
return;
}
apr_dbm_delete(dbm, dbmkey);
apr_dbm_close(dbm);
ssl_mutex_off(s);
return;
}
static void ssl_scache_dbm_expire(server_rec *s)
{
SSLModConfigRec *mc = myModConfig(s);
SSLSrvConfigRec *sc = mySrvConfig(s);
static time_t tLast = 0;
apr_dbm_t *dbm;
apr_datum_t dbmkey;
apr_datum_t dbmval;
apr_pool_t *p;
time_t tExpiresAt;
int nElements = 0;
int nDeleted = 0;
int bDelete;
apr_datum_t *keylist;
int keyidx;
int i;
time_t tNow;
apr_status_t rv;
/*
* make sure the expiration for still not-accessed session
* cache entries is done only from time to time
*/
tNow = time(NULL);
if (tNow < tLast+sc->session_cache_timeout)
return;
tLast = tNow;
/*
* Here we have to be very carefully: Not all DBM libraries are
* smart enough to allow one to iterate over the elements and at the
* same time delete expired ones. Some of them get totally crazy
* while others have no problems. So we have to do it the slower but
* more safe way: we first iterate over all elements and remember
* those which have to be expired. Then in a second pass we delete
* all those expired elements. Additionally we reopen the DBM file
* to be really safe in state.
*/
#define KEYMAX 1024
ssl_mutex_on(s);
for (;;) {
/* allocate the key array in a memory sub pool */
apr_pool_create_ex(&p, mc->pPool, NULL, NULL);
if (p == NULL)
break;
if ((keylist = apr_palloc(p, sizeof(dbmkey)*KEYMAX)) == NULL) {
apr_pool_destroy(p);
break;
}
/* pass 1: scan DBM database */
keyidx = 0;
if ((rv = apr_dbm_open(&dbm, mc->szSessionCacheDataFile,
APR_DBM_RWCREATE,SSL_DBM_FILE_MODE,
p)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, s,
"Cannot open SSLSessionCache DBM file `%s' for "
"scanning",
mc->szSessionCacheDataFile);
apr_pool_destroy(p);
break;
}
apr_dbm_firstkey(dbm, &dbmkey);
while (dbmkey.dptr != NULL) {
nElements++;
bDelete = FALSE;
apr_dbm_fetch(dbm, dbmkey, &dbmval);
if (dbmval.dsize <= sizeof(time_t) || dbmval.dptr == NULL)
bDelete = TRUE;
else {
memcpy(&tExpiresAt, dbmval.dptr, sizeof(time_t));
if (tExpiresAt <= tNow)
bDelete = TRUE;
}
if (bDelete) {
if ((keylist[keyidx].dptr = apr_pmemdup(p, dbmkey.dptr, dbmkey.dsize)) != NULL) {
keylist[keyidx].dsize = dbmkey.dsize;
keyidx++;
if (keyidx == KEYMAX)
break;
}
}
apr_dbm_nextkey(dbm, &dbmkey);
}
apr_dbm_close(dbm);
/* pass 2: delete expired elements */
if (apr_dbm_open(&dbm, mc->szSessionCacheDataFile,
APR_DBM_RWCREATE,SSL_DBM_FILE_MODE, p) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, s,
"Cannot re-open SSLSessionCache DBM file `%s' for "
"expiring",
mc->szSessionCacheDataFile);
apr_pool_destroy(p);
break;
}
for (i = 0; i < keyidx; i++) {
apr_dbm_delete(dbm, keylist[i]);
nDeleted++;
}
apr_dbm_close(dbm);
/* destroy temporary pool */
apr_pool_destroy(p);
if (keyidx < KEYMAX)
break;
}
ssl_mutex_off(s);
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
"Inter-Process Session Cache (DBM) Expiry: "
"old: %d, new: %d, removed: %d",
nElements, nElements-nDeleted, nDeleted);
return;
}
void ssl_scache_dbm_status(request_rec *r, int flags, apr_pool_t *p)
{
SSLModConfigRec *mc = myModConfig(r->server);
apr_dbm_t *dbm;
apr_datum_t dbmkey;
apr_datum_t dbmval;
int nElem;
int nSize;
int nAverage;
apr_status_t rv;
nElem = 0;
nSize = 0;
ssl_mutex_on(r->server);
/*
* XXX - Check what pool is to be used - TBD
*/
if ((rv = apr_dbm_open(&dbm, mc->szSessionCacheDataFile,
APR_DBM_RWCREATE, SSL_DBM_FILE_MODE,
mc->pPool)) != APR_SUCCESS) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
"Cannot open SSLSessionCache DBM file `%s' for status "
"retrival",
mc->szSessionCacheDataFile);
ssl_mutex_off(r->server);
return;
}
/*
* XXX - Check the return value of apr_dbm_firstkey, apr_dbm_fetch - TBD
*/
apr_dbm_firstkey(dbm, &dbmkey);
for ( ; dbmkey.dptr != NULL; apr_dbm_nextkey(dbm, &dbmkey)) {
apr_dbm_fetch(dbm, dbmkey, &dbmval);
if (dbmval.dptr == NULL)
continue;
nElem += 1;
nSize += dbmval.dsize;
}
apr_dbm_close(dbm);
ssl_mutex_off(r->server);
if (nSize > 0 && nElem > 0)
nAverage = nSize / nElem;
else
nAverage = 0;
ap_rprintf(r, "cache type: <b>DBM</b>, maximum size: <b>unlimited</b><br>");
ap_rprintf(r, "current sessions: <b>%d</b>, current size: <b>%d</b> bytes<br>", nElem, nSize);
ap_rprintf(r, "average session size: <b>%d</b> bytes<br>", nAverage);
return;
}