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/* 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.
*/
#include "httpd.h"
#include "http_log.h"
#include "http_request.h"
#include "http_config.h"
#include "http_protocol.h"
#include "mod_status.h"
#include "apr_strings.h"
#include "apr_time.h"
#include "ap_socache.h"
#include "distcache/dc_client.h"
#if !defined(DISTCACHE_CLIENT_API) || (DISTCACHE_CLIENT_API < 0x0001)
#error "You must compile with a more recent version of the distcache-base package"
#endif
struct ap_socache_instance_t {
/* Configured target server: */
const char *target;
/* distcache client context: */
DC_CTX *dc;
};
static const char *socache_dc_create(ap_socache_instance_t **context,
const char *arg,
apr_pool_t *tmp, apr_pool_t *p)
{
struct ap_socache_instance_t *ctx;
ctx = *context = apr_palloc(p, sizeof *ctx);
ctx->target = apr_pstrdup(p, arg);
return NULL;
}
static apr_status_t socache_dc_init(ap_socache_instance_t *ctx,
const char *namespace,
const struct ap_socache_hints *hints,
server_rec *s, apr_pool_t *p)
{
#if 0
/* If a "persistent connection" mode of operation is preferred, you *must*
* also use the PIDCHECK flag to ensure fork()'d processes don't interlace
* comms on the same connection as each other. */
#define SESSION_CTX_FLAGS SESSION_CTX_FLAG_PERSISTENT | \
SESSION_CTX_FLAG_PERSISTENT_PIDCHECK | \
SESSION_CTX_FLAG_PERSISTENT_RETRY | \
SESSION_CTX_FLAG_PERSISTENT_LATE
#else
/* This mode of operation will open a temporary connection to the 'target'
* for each cache operation - this makes it safe against fork()
* automatically. This mode is preferred when running a local proxy (over
* unix domain sockets) because overhead is negligible and it reduces the
* performance/stability danger of file-descriptor bloatage. */
#define SESSION_CTX_FLAGS 0
#endif
ctx->dc = DC_CTX_new(ctx->target, SESSION_CTX_FLAGS);
if (!ctx->dc) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(00738) "distributed scache failed to obtain context");
return APR_EGENERAL;
}
ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(00739) "distributed scache context initialised");
return APR_SUCCESS;
}
static void socache_dc_destroy(ap_socache_instance_t *ctx, server_rec *s)
{
if (ctx && ctx->dc) {
DC_CTX_free(ctx->dc);
ctx->dc = NULL;
}
}
static apr_status_t socache_dc_store(ap_socache_instance_t *ctx, server_rec *s,
const unsigned char *id, unsigned int idlen,
apr_time_t expiry,
unsigned char *der, unsigned int der_len,
apr_pool_t *p)
{
/* !@#$%^ - why do we deal with *absolute* time anyway???
* Uhm - because most things expire things at a specific time?
* Were the API were thought out expiry - r->request_time is a good approximation
*/
expiry -= apr_time_now();
/* Send the serialised session to the distributed cache context */
if (!DC_CTX_add_session(ctx->dc, id, idlen, der, der_len,
apr_time_msec(expiry))) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(00740) "distributed scache 'store' failed");
return APR_EGENERAL;
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(00741) "distributed scache 'store' successful");
return APR_SUCCESS;
}
static apr_status_t socache_dc_retrieve(ap_socache_instance_t *ctx, server_rec *s,
const unsigned char *id, unsigned int idlen,
unsigned char *dest, unsigned int *destlen,
apr_pool_t *p)
{
unsigned int data_len;
/* Retrieve any corresponding session from the distributed cache context */
if (!DC_CTX_get_session(ctx->dc, id, idlen, dest, *destlen, &data_len)) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(00742) "distributed scache 'retrieve' MISS");
return APR_NOTFOUND;
}
if (data_len > *destlen) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(00743) "distributed scache 'retrieve' OVERFLOW");
return APR_ENOSPC;
}
*destlen = data_len;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(00744) "distributed scache 'retrieve' HIT");
return APR_SUCCESS;
}
static apr_status_t socache_dc_remove(ap_socache_instance_t *ctx,
server_rec *s, const unsigned char *id,
unsigned int idlen, apr_pool_t *p)
{
/* Remove any corresponding session from the distributed cache context */
if (!DC_CTX_remove_session(ctx->dc, id, idlen)) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(00745) "distributed scache 'remove' MISS");
return APR_NOTFOUND;
}
else {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(00746) "distributed scache 'remove' HIT");
return APR_SUCCESS;
}
}
static void socache_dc_status(ap_socache_instance_t *ctx, request_rec *r, int flags)
{
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00747)
"distributed scache 'socache_dc_status'");
if (!(flags & AP_STATUS_SHORT)) {
ap_rprintf(r, "cache type: <b>DC (Distributed Cache)</b>, "
" target: <b>%s</b><br>", ctx->target);
}
else {
ap_rputs("CacheType: DC\n", r);
ap_rvputs(r, "CacheTarget: ", ctx->target, "\n", NULL);
}
}
static apr_status_t socache_dc_iterate(ap_socache_instance_t *instance,
server_rec *s, void *userctx,
ap_socache_iterator_t *iterator,
apr_pool_t *pool)
{
return APR_ENOTIMPL;
}
static const ap_socache_provider_t socache_dc = {
"distcache",
0,
socache_dc_create,
socache_dc_init,
socache_dc_destroy,
socache_dc_store,
socache_dc_retrieve,
socache_dc_remove,
socache_dc_status,
socache_dc_iterate
};
static void register_hooks(apr_pool_t *p)
{
ap_register_provider(p, AP_SOCACHE_PROVIDER_GROUP, "dc",
AP_SOCACHE_PROVIDER_VERSION,
&socache_dc);
}
AP_DECLARE_MODULE(socache_dc) = {
STANDARD20_MODULE_STUFF,
NULL, NULL, NULL, NULL, NULL,
register_hooks
};
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