/* 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_config.h"

#include "http_protocol.h"

#include "apr.h"

#include "apu_version.h"

/* apr_memcache support requires >= 1.3 */

#if APU_MAJOR_VERSION > 1 || \

    (APU_MAJOR_VERSION == 1 && APU_MINOR_VERSION > 2)

#define HAVE_APU_MEMCACHE 1

#endif

#ifdef HAVE_APU_MEMCACHE

#include "ap_socache.h"

#include "ap_mpm.h"

#include "http_log.h"

#include "apr_memcache.h"

#include "apr_strings.h"

#include "mod_status.h"

/* The underlying apr_memcache system is thread safe.. */

#define MC_KEY_LEN 254

#ifndef MC_DEFAULT_SERVER_PORT

#define MC_DEFAULT_SERVER_PORT 11211

#endif

#ifndef MC_DEFAULT_SERVER_MIN

#define MC_DEFAULT_SERVER_MIN 0

#endif

#ifndef MC_DEFAULT_SERVER_SMAX

#define MC_DEFAULT_SERVER_SMAX 1

#endif

#ifndef MC_DEFAULT_SERVER_TTL

#define MC_DEFAULT_SERVER_TTL    apr_time_from_sec(15)

#endif

module AP_MODULE_DECLARE_DATA socache_memcache_module;

typedef struct {

    apr_uint32_t ttl;

} socache_mc_svr_cfg;

struct ap_socache_instance_t {

    const char *servers;

    apr_memcache_t *mc;

    const char *tag;

    apr_size_t taglen; /* strlen(tag) + 1 */

};

static const char *socache_mc_create(ap_socache_instance_t **context,

                                     const char *arg,

                                     apr_pool_t *tmp, apr_pool_t *p)

{

    ap_socache_instance_t *ctx;

    *context = ctx = apr_palloc(p, sizeof *ctx);

    if (!arg || !*arg) {

        return "List of server names required to create memcache socache.";

    }

    ctx->servers = apr_pstrdup(p, arg);

    return NULL;

}

static apr_status_t socache_mc_init(ap_socache_instance_t *ctx,

                                    const char *namespace,

                                    const struct ap_socache_hints *hints,

                                    server_rec *s, apr_pool_t *p)

{

    apr_status_t rv;

    int thread_limit = 0;

    apr_uint16_t nservers = 0;

    char *cache_config;

    char *split;

    char *tok;

    socache_mc_svr_cfg *sconf = ap_get_module_config(s->module_config,

                                                     &socache_memcache_module);

    ap_mpm_query(AP_MPMQ_HARD_LIMIT_THREADS, &thread_limit);

    /* Find all the servers in the first run to get a total count */

    cache_config = apr_pstrdup(p, ctx->servers);

    split = apr_strtok(cache_config, ",", &tok;;

    while (split) {

        nservers++;

        split = apr_strtok(NULL,",", &tok;;

    }

    rv = apr_memcache_create(p, nservers, 0, &ctx->mc);

    if (rv != APR_SUCCESS) {

        ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(00785)

                     "Failed to create Memcache Object of '%d' size.",

                     nservers);

        return rv;

    }

    /* Now add each server to the memcache */

    cache_config = apr_pstrdup(p, ctx->servers);

    split = apr_strtok(cache_config, ",", &tok;;

    while (split) {

        apr_memcache_server_t *st;

        char *host_str;

        char *scope_id;

        apr_port_t port;

        rv = apr_parse_addr_port(&host_str, &scope_id, &port, split, p);

        if (rv != APR_SUCCESS) {

            ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(00786)

                         "Failed to Parse memcache Server: '%s'", split);

            return rv;

        }

        if (host_str == NULL) {

            ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(00787)

                         "Failed to Parse Server, "

                         "no hostname specified: '%s'", split);

            return APR_EINVAL;

        }

        if (port == 0) {

            port = MC_DEFAULT_SERVER_PORT;

        }

        rv = apr_memcache_server_create(p,

                                        host_str, port,

                                        MC_DEFAULT_SERVER_MIN,

                                        MC_DEFAULT_SERVER_SMAX,

                                        thread_limit,

                                        sconf->ttl,

                                        &st);

        if (rv != APR_SUCCESS) {

            ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(00788)

                         "Failed to Create memcache Server: %s:%d",

                         host_str, port);

            return rv;

        }

        rv = apr_memcache_add_server(ctx->mc, st);

        if (rv != APR_SUCCESS) {

            ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(00789)

                         "Failed to Add memcache Server: %s:%d",

                         host_str, port);

            return rv;

        }

        split = apr_strtok(NULL,",", &tok;;

    }

    ctx->tag = apr_pstrcat(p, namespace, ":", NULL);

    ctx->taglen = strlen(ctx->tag) + 1;

    /* socache API constraint: */

    AP_DEBUG_ASSERT(ctx->taglen <= 16);

    return APR_SUCCESS;

}

static void socache_mc_destroy(ap_socache_instance_t *context, server_rec *s)

{

    /* noop. */

}

/* Converts (binary) id into a key prefixed by the predetermined

 * namespace tag; writes output to key buffer.  Returns non-zero if

 * the id won't fit in the key buffer. */

static int socache_mc_id2key(ap_socache_instance_t *ctx,

                             const unsigned char *id, unsigned int idlen,

                             char *key, apr_size_t keylen)

{

    char *cp;

    if (idlen * 2 + ctx->taglen >= keylen)

        return 1;

    cp = apr_cpystrn(key, ctx->tag, ctx->taglen);

    ap_bin2hex(id, idlen, cp);

    return 0;

}

static apr_status_t socache_mc_store(ap_socache_instance_t *ctx, server_rec *s,

                                     const unsigned char *id, unsigned int idlen,

                                     apr_time_t expiry,

                                     unsigned char *ucaData, unsigned int nData,

                                     apr_pool_t *p)

{

    char buf[MC_KEY_LEN];

    apr_status_t rv;

    if (socache_mc_id2key(ctx, id, idlen, buf, sizeof buf)) {

        return APR_EINVAL;

    }

    /* memcache needs time in seconds till expiry; fail if this is not

     * positive *before* casting to unsigned (apr_uint32_t). */

    expiry -= apr_time_now();

    if (apr_time_sec(expiry) <= 0) {

        return APR_EINVAL;

    }

    rv = apr_memcache_set(ctx->mc, buf, (char*)ucaData, nData,

                          apr_time_sec(expiry), 0);

    if (rv != APR_SUCCESS) {

        ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(00790)

                     "scache_mc: error setting key '%s' "

                     "with %d bytes of data", buf, nData);

        return rv;

    }

    return APR_SUCCESS;

}

static apr_status_t socache_mc_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)

{

    apr_size_t data_len;

    char buf[MC_KEY_LEN], *data;

    apr_status_t rv;

    if (socache_mc_id2key(ctx, id, idlen, buf, sizeof buf)) {

        return APR_EINVAL;

    }

    /* ### this could do with a subpool, but _getp looks like it will

     * eat memory like it's going out of fashion anyway. */

    rv = apr_memcache_getp(ctx->mc, p, buf, &data, &data_len, NULL);

    if (rv) {

        if (rv != APR_NOTFOUND) {

            ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(00791)

                         "scache_mc: 'retrieve' FAIL");

        }

        return rv;

    }

    else if (data_len > *destlen) {

        ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(00792)

                     "scache_mc: 'retrieve' OVERFLOW");

        return APR_ENOMEM;

    }

    memcpy(dest, data, data_len);

    *destlen = data_len;

    return APR_SUCCESS;

}

static apr_status_t socache_mc_remove(ap_socache_instance_t *ctx, server_rec *s,

                                      const unsigned char *id,

                                      unsigned int idlen, apr_pool_t *p)

{

    char buf[MC_KEY_LEN];

    apr_status_t rv;

    if (socache_mc_id2key(ctx, id, idlen, buf, sizeof buf)) {

        return APR_EINVAL;

    }

    rv = apr_memcache_delete(ctx->mc, buf, 0);

    if (rv != APR_SUCCESS) {

        ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, s, APLOGNO(00793)

                     "scache_mc: error deleting key '%s' ",

                     buf);

    }

    return rv;

}

static void socache_mc_status(ap_socache_instance_t *ctx, request_rec *r, int flags)

{

    apr_memcache_t *rc = ctx->mc;

    int i;

    for (i = 0; i < rc->ntotal; i++) {

        apr_memcache_server_t *ms;

        apr_memcache_stats_t *stats;

        apr_status_t rv;

        char *br = (!(flags & AP_STATUS_SHORT) ? "
" : "");

        ms = rc->live_servers[i];

        ap_rprintf(r, "Memcached server: %s:%d [%s]%s\n", ms->host, (int)ms->port,

                (ms->status == APR_MC_SERVER_LIVE) ? "Up" : "Down",

                br);

        rv = apr_memcache_stats(ms, r->pool, &stats);

        if (rv != APR_SUCCESS)

            continue;

        if (!(flags & AP_STATUS_SHORT)) {

            ap_rprintf(r, "Version: %s [%u bits], PID: %u, Uptime: %u hrs 
\n",

                    stats->version , stats->pointer_size, stats->pid, stats->uptime/3600);

            ap_rprintf(r, "Clients:: Structures: %u, Total: %u, Current: %u 
\n",

                    stats->connection_structures, stats->total_connections, stats->curr_connections);

            ap_rprintf(r, "Storage:: Total Items: %u, Current Items: %u, Bytes: %" APR_UINT64_T_FMT " 
\n",

                    stats->total_items, stats->curr_items, stats->bytes);

            ap_rprintf(r, "CPU:: System: %u, User: %u 
\n",

                    (unsigned)stats->rusage_system, (unsigned)stats->rusage_user );

            ap_rprintf(r, "Cache:: Gets: %u, Sets: %u, Hits: %u, Misses: %u 
\n",

                    stats->cmd_get, stats->cmd_set, stats->get_hits, stats->get_misses);

            ap_rprintf(r, "Net:: Input bytes: %" APR_UINT64_T_FMT ", Output bytes: %" APR_UINT64_T_FMT " 
\n",

                    stats->bytes_read, stats->bytes_written);

            ap_rprintf(r, "Misc:: Evictions: %" APR_UINT64_T_FMT ", MaxMem: %u, Threads: %u 
\n",

                    stats->evictions, stats->limit_maxbytes, stats->threads);

            ap_rputs("

\n", r);

        }

        else {

            ap_rprintf(r, "Version: %s [%u bits], PID: %u, Uptime: %u hrs %s\n",

                    stats->version , stats->pointer_size, stats->pid, stats->uptime/3600, br);

            ap_rprintf(r, "Clients:: Structures: %d, Total: %d, Current: %u %s\n",

                    stats->connection_structures, stats->total_connections, stats->curr_connections, br);

            ap_rprintf(r, "Storage:: Total Items: %u, Current Items: %u, Bytes: %" APR_UINT64_T_FMT " %s\n",

                    stats->total_items, stats->curr_items, stats->bytes, br);

            ap_rprintf(r, "CPU:: System: %u, User: %u %s\n",

                    (unsigned)stats->rusage_system, (unsigned)stats->rusage_user , br);

            ap_rprintf(r, "Cache:: Gets: %u, Sets: %u, Hits: %u, Misses: %u %s\n",

                    stats->cmd_get, stats->cmd_set, stats->get_hits, stats->get_misses, br);

            ap_rprintf(r, "Net:: Input bytes: %" APR_UINT64_T_FMT ", Output bytes: %" APR_UINT64_T_FMT " %s\n",

                    stats->bytes_read, stats->bytes_written, br);

            ap_rprintf(r, "Misc:: Evictions: %" APR_UINT64_T_FMT ", MaxMem: %u, Threads: %u %s\n",

                    stats->evictions, stats->limit_maxbytes, stats->threads, br);

        }

    }

}

static apr_status_t socache_mc_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_mc = {

    "memcache",

    0,

    socache_mc_create,

    socache_mc_init,

    socache_mc_destroy,

    socache_mc_store,

    socache_mc_retrieve,

    socache_mc_remove,

    socache_mc_status,

    socache_mc_iterate

};

#endif /* HAVE_APU_MEMCACHE */

static void *create_server_config(apr_pool_t *p, server_rec *s)

{

    socache_mc_svr_cfg *sconf = apr_pcalloc(p, sizeof(socache_mc_svr_cfg));

    sconf->ttl = MC_DEFAULT_SERVER_TTL;

    return sconf;

}

static const char *socache_mc_set_ttl(cmd_parms *cmd, void *dummy,

                                      const char *arg)

{

    apr_interval_time_t ttl;

    socache_mc_svr_cfg *sconf = ap_get_module_config(cmd->server->module_config,

                                                     &socache_memcache_module);

    if (ap_timeout_parameter_parse(arg, &ttl, "s") != APR_SUCCESS) {

        return apr_pstrcat(cmd->pool, cmd->cmd->name,

                           " has wrong format", NULL);

    }

    if ((ttl < apr_time_from_sec(0)) || (ttl > apr_time_from_sec(3600))) {

        return apr_pstrcat(cmd->pool, cmd->cmd->name,

                           " can only be 0 or up to one hour.", NULL);

    }

    /* apr_memcache_server_create needs a ttl in usec. */

    sconf->ttl = ttl;

    return NULL;

}

static void register_hooks(apr_pool_t *p)

{

#ifdef HAVE_APU_MEMCACHE

    ap_register_provider(p, AP_SOCACHE_PROVIDER_GROUP, "memcache",

                         AP_SOCACHE_PROVIDER_VERSION,

                         &socache_mc);

#endif

}

static const command_rec socache_memcache_cmds[] = {

    AP_INIT_TAKE1("MemcacheConnTTL", socache_mc_set_ttl, NULL, RSRC_CONF,

                  "TTL used for the connection with the memcache server(s)"),

    { NULL }

};

AP_DECLARE_MODULE(socache_memcache) = {

    STANDARD20_MODULE_STUFF,

    NULL,                     /* create per-dir    config structures */

    NULL,                     /* merge  per-dir    config structures */

    create_server_config,     /* create per-server config structures */

    NULL,                     /* merge  per-server config structures */

    socache_memcache_cmds,    /* table of config file commands       */

    register_hooks            /* register hooks                      */

};