diff options
Diffstat (limited to 'modules/cache/mod_socache_dbm.c')
| -rw-r--r-- | modules/cache/mod_socache_dbm.c | 595 |
1 files changed, 595 insertions, 0 deletions
diff --git a/modules/cache/mod_socache_dbm.c b/modules/cache/mod_socache_dbm.c new file mode 100644 index 0000000..579d2ff --- /dev/null +++ b/modules/cache/mod_socache_dbm.c @@ -0,0 +1,595 @@ +/* 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_protocol.h" +#include "http_config.h" +#include "mpm_common.h" +#include "mod_status.h" + +#include "apr.h" +#include "apr_strings.h" +#include "apr_time.h" +#define APR_WANT_STRFUNC +#include "apr_want.h" +#include "apr_dbm.h" + +#if APR_HAVE_UNISTD_H +#include <unistd.h> +#endif + +#include "ap_socache.h" + +#if AP_NEED_SET_MUTEX_PERMS +#include "unixd.h" +#endif + +/* Use of the context structure must be thread-safe after the initial + * create/init; callers must hold the mutex. */ +struct ap_socache_instance_t { + const char *data_file; + /* Pool must only be used with the mutex held. */ + apr_pool_t *pool; + apr_time_t last_expiry; + apr_interval_time_t expiry_interval; +}; + +/** + * Support for DBM library + */ +#define DBM_FILE_MODE ( APR_UREAD | APR_UWRITE | APR_GREAD | APR_WREAD ) + +#define DEFAULT_DBM_PREFIX "socache-dbm-" + +/* ### this should use apr_dbm_usednames. */ +#if !defined(DBM_FILE_SUFFIX_DIR) && !defined(DBM_FILE_SUFFIX_PAG) +#if defined(DBM_SUFFIX) +#define DBM_FILE_SUFFIX_DIR DBM_SUFFIX +#define DBM_FILE_SUFFIX_PAG DBM_SUFFIX +#elif defined(__FreeBSD__) || (defined(DB_LOCK) && defined(DB_SHMEM)) +#define DBM_FILE_SUFFIX_DIR ".db" +#define DBM_FILE_SUFFIX_PAG ".db" +#else +#define DBM_FILE_SUFFIX_DIR ".dir" +#define DBM_FILE_SUFFIX_PAG ".pag" +#endif +#endif + +static void socache_dbm_expire(ap_socache_instance_t *ctx, server_rec *s); + +static apr_status_t socache_dbm_remove(ap_socache_instance_t *ctx, + server_rec *s, const unsigned char *id, + unsigned int idlen, apr_pool_t *p); + +static const char *socache_dbm_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_pcalloc(p, sizeof *ctx); + + if (arg && *arg) { + ctx->data_file = ap_server_root_relative(p, arg); + if (!ctx->data_file) { + return apr_psprintf(tmp, "Invalid cache file path %s", arg); + } + } + + apr_pool_create(&ctx->pool, p); + + return NULL; +} + +#if AP_NEED_SET_MUTEX_PERMS +static int try_chown(apr_pool_t *p, server_rec *s, + const char *name, const char *suffix) +{ + if (suffix) + name = apr_pstrcat(p, name, suffix, NULL); + if (-1 == chown(name, ap_unixd_config.user_id, + (gid_t)-1 /* no gid change */ )) + { + if (errno != ENOENT) + ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(errno), s, APLOGNO(00802) + "Can't change owner of %s", name); + return -1; + } + return 0; +} +#endif + + +static apr_status_t socache_dbm_init(ap_socache_instance_t *ctx, + const char *namespace, + const struct ap_socache_hints *hints, + server_rec *s, apr_pool_t *p) +{ + apr_dbm_t *dbm; + apr_status_t rv; + + /* for the DBM we need the data file */ + if (ctx->data_file == NULL) { + const char *path = apr_pstrcat(p, DEFAULT_DBM_PREFIX, namespace, + NULL); + + ctx->data_file = ap_runtime_dir_relative(p, path); + + if (ctx->data_file == NULL) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(00803) + "could not use default path '%s' for DBM socache", + path); + return APR_EINVAL; + } + } + + /* open it once to create it and to make sure it _can_ be created */ + apr_pool_clear(ctx->pool); + + if ((rv = apr_dbm_open(&dbm, ctx->data_file, + APR_DBM_RWCREATE, DBM_FILE_MODE, ctx->pool)) != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(00804) + "Cannot create socache DBM file `%s'", + ctx->data_file); + return rv; + } + apr_dbm_close(dbm); + + ctx->expiry_interval = (hints && hints->expiry_interval + ? hints->expiry_interval : apr_time_from_sec(30)); + +#if AP_NEED_SET_MUTEX_PERMS + /* + * 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 */) { + try_chown(p, s, ctx->data_file, NULL); + if (try_chown(p, s, ctx->data_file, DBM_FILE_SUFFIX_DIR)) + if (try_chown(p, s, ctx->data_file, ".db")) + try_chown(p, s, ctx->data_file, ".dir"); + if (try_chown(p, s, ctx->data_file, DBM_FILE_SUFFIX_PAG)) + if (try_chown(p, s, ctx->data_file, ".db")) + try_chown(p, s, ctx->data_file, ".pag"); + } +#endif + socache_dbm_expire(ctx, s); + + return APR_SUCCESS; +} + +static void socache_dbm_destroy(ap_socache_instance_t *ctx, server_rec *s) +{ + /* the correct way */ + unlink(apr_pstrcat(ctx->pool, ctx->data_file, DBM_FILE_SUFFIX_DIR, NULL)); + unlink(apr_pstrcat(ctx->pool, ctx->data_file, DBM_FILE_SUFFIX_PAG, NULL)); + /* the additional ways to be sure */ + unlink(apr_pstrcat(ctx->pool, ctx->data_file, ".dir", NULL)); + unlink(apr_pstrcat(ctx->pool, ctx->data_file, ".pag", NULL)); + unlink(apr_pstrcat(ctx->pool, ctx->data_file, ".db", NULL)); + unlink(ctx->data_file); +} + +static apr_status_t socache_dbm_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 *pool) +{ + apr_dbm_t *dbm; + apr_datum_t dbmkey; + apr_datum_t dbmval; + apr_status_t rv; + + /* 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, APLOGNO(00805) + "data size too large for DBM socache: %d >= %d", + (idlen + nData), PAIRMAX); + return APR_ENOSPC; + } +#else + if ((idlen + nData) >= 950 /* at least less than approx. 1KB */) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(00806) + "data size too large for DBM socache: %d >= %d", + (idlen + nData), 950); + return APR_ENOSPC; + } +#endif + + /* create DBM key */ + dbmkey.dptr = (char *)id; + dbmkey.dsize = idlen; + + /* create DBM value */ + dbmval.dsize = sizeof(apr_time_t) + nData; + dbmval.dptr = (char *)ap_malloc(dbmval.dsize); + memcpy((char *)dbmval.dptr, &expiry, sizeof(apr_time_t)); + memcpy((char *)dbmval.dptr+sizeof(apr_time_t), ucaData, nData); + + /* and store it to the DBM file */ + apr_pool_clear(ctx->pool); + + if ((rv = apr_dbm_open(&dbm, ctx->data_file, + APR_DBM_RWCREATE, DBM_FILE_MODE, ctx->pool)) != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(00807) + "Cannot open socache DBM file `%s' for writing " + "(store)", + ctx->data_file); + free(dbmval.dptr); + return rv; + } + if ((rv = apr_dbm_store(dbm, dbmkey, dbmval)) != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(00808) + "Cannot store socache object to DBM file `%s'", + ctx->data_file); + apr_dbm_close(dbm); + free(dbmval.dptr); + return rv; + } + apr_dbm_close(dbm); + + /* free temporary buffers */ + free(dbmval.dptr); + + /* allow the regular expiring to occur */ + socache_dbm_expire(ctx, s); + + return APR_SUCCESS; +} + +static apr_status_t socache_dbm_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_dbm_t *dbm; + apr_datum_t dbmkey; + apr_datum_t dbmval; + unsigned int nData; + apr_time_t expiry; + apr_time_t now; + apr_status_t rc; + + /* allow the regular expiring to occur */ + socache_dbm_expire(ctx, 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. + */ + apr_pool_clear(ctx->pool); + if ((rc = apr_dbm_open(&dbm, ctx->data_file, APR_DBM_RWCREATE, + DBM_FILE_MODE, ctx->pool)) != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ERR, rc, s, APLOGNO(00809) + "Cannot open socache DBM file `%s' for reading " + "(fetch)", + ctx->data_file); + return rc; + } + rc = apr_dbm_fetch(dbm, dbmkey, &dbmval); + if (rc != APR_SUCCESS) { + apr_dbm_close(dbm); + return APR_NOTFOUND; + } + if (dbmval.dptr == NULL || dbmval.dsize <= sizeof(apr_time_t)) { + apr_dbm_close(dbm); + return APR_EGENERAL; + } + + /* parse resulting data */ + nData = dbmval.dsize-sizeof(apr_time_t); + if (nData > *destlen) { + apr_dbm_close(dbm); + return APR_ENOSPC; + } + + *destlen = nData; + memcpy(&expiry, dbmval.dptr, sizeof(apr_time_t)); + memcpy(dest, (char *)dbmval.dptr + sizeof(apr_time_t), nData); + + apr_dbm_close(dbm); + + /* make sure the stuff is still not expired */ + now = apr_time_now(); + if (expiry <= now) { + socache_dbm_remove(ctx, s, id, idlen, p); + return APR_NOTFOUND; + } + + return APR_SUCCESS; +} + +static apr_status_t socache_dbm_remove(ap_socache_instance_t *ctx, + server_rec *s, const unsigned char *id, + unsigned int idlen, apr_pool_t *p) +{ + 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 */ + apr_pool_clear(ctx->pool); + + if ((rv = apr_dbm_open(&dbm, ctx->data_file, APR_DBM_RWCREATE, + DBM_FILE_MODE, ctx->pool)) != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(00810) + "Cannot open socache DBM file `%s' for writing " + "(delete)", + ctx->data_file); + return rv; + } + apr_dbm_delete(dbm, dbmkey); + apr_dbm_close(dbm); + + return APR_SUCCESS; +} + +static void socache_dbm_expire(ap_socache_instance_t *ctx, server_rec *s) +{ + apr_dbm_t *dbm; + apr_datum_t dbmkey; + apr_datum_t dbmval; + apr_time_t expiry; + int elts = 0; + int deleted = 0; + int expired; + apr_datum_t *keylist; + int keyidx; + int i; + apr_time_t now; + apr_status_t rv; + + /* + * make sure the expiration for still not-accessed + * socache entries is done only from time to time + */ + now = apr_time_now(); + + if (now < ctx->last_expiry + ctx->expiry_interval) { + return; + } + + ctx->last_expiry = now; + + /* + * 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 + + for (;;) { + /* allocate the key array in a memory sub pool */ + apr_pool_clear(ctx->pool); + + if ((keylist = apr_palloc(ctx->pool, sizeof(dbmkey)*KEYMAX)) == NULL) { + break; + } + + /* pass 1: scan DBM database */ + keyidx = 0; + if ((rv = apr_dbm_open(&dbm, ctx->data_file, APR_DBM_RWCREATE, + DBM_FILE_MODE, ctx->pool)) != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(00811) + "Cannot open socache DBM file `%s' for " + "scanning", + ctx->data_file); + break; + } + apr_dbm_firstkey(dbm, &dbmkey); + while (dbmkey.dptr != NULL) { + elts++; + expired = FALSE; + apr_dbm_fetch(dbm, dbmkey, &dbmval); + if (dbmval.dsize <= sizeof(apr_time_t) || dbmval.dptr == NULL) + expired = TRUE; + else { + memcpy(&expiry, dbmval.dptr, sizeof(apr_time_t)); + if (expiry <= now) + expired = TRUE; + } + if (expired) { + if ((keylist[keyidx].dptr = apr_pmemdup(ctx->pool, 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, ctx->data_file, APR_DBM_RWCREATE, + DBM_FILE_MODE, ctx->pool) != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(00812) + "Cannot re-open socache DBM file `%s' for " + "expiring", + ctx->data_file); + break; + } + for (i = 0; i < keyidx; i++) { + apr_dbm_delete(dbm, keylist[i]); + deleted++; + } + apr_dbm_close(dbm); + + if (keyidx < KEYMAX) + break; + } + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(00813) + "DBM socache expiry: " + "old: %d, new: %d, removed: %d", + elts, elts-deleted, deleted); +} + +static void socache_dbm_status(ap_socache_instance_t *ctx, request_rec *r, + int flags) +{ + apr_dbm_t *dbm; + apr_datum_t dbmkey; + apr_datum_t dbmval; + int elts; + long size; + int avg; + apr_status_t rv; + + elts = 0; + size = 0; + + apr_pool_clear(ctx->pool); + if ((rv = apr_dbm_open(&dbm, ctx->data_file, APR_DBM_RWCREATE, + DBM_FILE_MODE, ctx->pool)) != APR_SUCCESS) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(00814) + "Cannot open socache DBM file `%s' for status " + "retrival", + ctx->data_file); + 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; + elts += 1; + size += dbmval.dsize; + } + apr_dbm_close(dbm); + if (size > 0 && elts > 0) + avg = (int)(size / (long)elts); + else + avg = 0; + if (!(flags & AP_STATUS_SHORT)) { + ap_rprintf(r, "cache type: <b>DBM</b>, maximum size: <b>unlimited</b><br>"); + ap_rprintf(r, "current entries: <b>%d</b>, current size: <b>%ld</b> bytes<br>", elts, size); + ap_rprintf(r, "average entry size: <b>%d</b> bytes<br>", avg); + } + else { + ap_rputs("CacheType: DBM\n", r); + ap_rputs("CacheMaximumSize: unlimited\n", r); + ap_rprintf(r, "CacheCurrentEntries: %d\n", elts); + ap_rprintf(r, "CacheCurrentSize: %ld\n", size); + ap_rprintf(r, "CacheAvgEntrySize: %d\n", avg); + } +} + +static apr_status_t socache_dbm_iterate(ap_socache_instance_t *ctx, + server_rec *s, void *userctx, + ap_socache_iterator_t *iterator, + apr_pool_t *pool) +{ + apr_dbm_t *dbm; + apr_datum_t dbmkey; + apr_datum_t dbmval; + apr_time_t expiry; + int expired; + apr_time_t now; + apr_status_t rv; + + /* + * make sure the expired records are omitted + */ + now = apr_time_now(); + if ((rv = apr_dbm_open(&dbm, ctx->data_file, APR_DBM_RWCREATE, + DBM_FILE_MODE, ctx->pool)) != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(00815) + "Cannot open socache DBM file `%s' for " + "iterating", ctx->data_file); + return rv; + } + rv = apr_dbm_firstkey(dbm, &dbmkey); + while (rv == APR_SUCCESS && dbmkey.dptr != NULL) { + expired = FALSE; + apr_dbm_fetch(dbm, dbmkey, &dbmval); + if (dbmval.dsize <= sizeof(apr_time_t) || dbmval.dptr == NULL) + expired = TRUE; + else { + memcpy(&expiry, dbmval.dptr, sizeof(apr_time_t)); + if (expiry <= now) + expired = TRUE; + } + if (!expired) { + rv = iterator(ctx, s, userctx, + (unsigned char *)dbmkey.dptr, dbmkey.dsize, + (unsigned char *)dbmval.dptr + sizeof(apr_time_t), + dbmval.dsize - sizeof(apr_time_t), pool); + ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, s, APLOGNO(00816) + "dbm `%s' entry iterated", ctx->data_file); + if (rv != APR_SUCCESS) + return rv; + } + rv = apr_dbm_nextkey(dbm, &dbmkey); + } + apr_dbm_close(dbm); + + if (rv != APR_SUCCESS && rv != APR_EOF) { + ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(00817) + "Failure reading first/next socache DBM file `%s' record", + ctx->data_file); + return rv; + } + return APR_SUCCESS; +} + +static const ap_socache_provider_t socache_dbm = { + "dbm", + AP_SOCACHE_FLAG_NOTMPSAFE, + socache_dbm_create, + socache_dbm_init, + socache_dbm_destroy, + socache_dbm_store, + socache_dbm_retrieve, + socache_dbm_remove, + socache_dbm_status, + socache_dbm_iterate +}; + +static void register_hooks(apr_pool_t *p) +{ + ap_register_provider(p, AP_SOCACHE_PROVIDER_GROUP, "dbm", + AP_SOCACHE_PROVIDER_VERSION, + &socache_dbm); +} + +AP_DECLARE_MODULE(socache_dbm) = { + STANDARD20_MODULE_STUFF, + NULL, NULL, NULL, NULL, NULL, + register_hooks +}; |