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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 "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 negligable 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, "distributed scache failed to obtain context");
return APR_EGENERAL;
}
ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, "distributed scache context initialised");
return APR_SUCCESS;
}
static void socache_dc_kill(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,
time_t timeout,
unsigned char *der, unsigned int der_len)
{
/* !@#$%^ - why do we deal with *absolute* time anyway??? */
timeout -= time(NULL);
/* Send the serialised session to the distributed cache context */
if (!DC_CTX_add_session(ctx->dc, id, idlen, der, der_len,
(unsigned long)timeout * 1000)) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "distributed scache 'add_session' failed");
return APR_EGENERAL;
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, "distributed scache 'add_session' 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, "distributed scache 'get_session' MISS");
return APR_EGENERAL;
}
if (data_len > *destlen) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "distributed scache 'get_session' OVERFLOW");
return APR_ENOSPC;
}
*destlen = data_len;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, "distributed scache 'get_session' HIT");
return APR_SUCCESS;
}
static void 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, "distributed scache 'remove_session' MISS");
} else {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "distributed scache 'remove_session' HIT");
}
}
static void socache_dc_status(ap_socache_instance_t *ctx, request_rec *r, int flags)
{
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
"distributed scache 'socache_dc_status'");
ap_rprintf(r, "cache type: <b>DC (Distributed Cache)</b>, "
" target: <b>%s</b><br>", ctx->target);
}
static const ap_socache_provider_t socache_dc = {
"distcache",
0,
socache_dc_create,
socache_dc_init,
socache_dc_kill,
socache_dc_store,
socache_dc_retrieve,
socache_dc_remove,
socache_dc_status
};
static void register_hooks(apr_pool_t *p)
{
ap_register_provider(p, AP_SOCACHE_PROVIDER_GROUP, "dc",
AP_SOCACHE_PROVIDER_VERSION,
&socache_dc);
}
module AP_MODULE_DECLARE_DATA socache_dc_module = {
STANDARD20_MODULE_STUFF,
NULL, NULL, NULL, NULL, NULL,
register_hooks
};
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