blob: f4eaa84c33f1dd4e2bdbf003933371230513ac02 [file] [log] [blame]
/* 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.
*/
/* Memory handler for a shared memory divided in slot.
* This one uses shared memory.
*
* Shared memory is cleaned-up for each restart, graceful or
* otherwise.
*/
#include "ap_slotmem.h"
#include "httpd.h"
#include "http_main.h"
#include "ap_mpm.h" /* for ap_mpm_query() */
#define AP_SLOTMEM_IS_PREGRAB(t) (t->desc->type & AP_SLOTMEM_TYPE_PREGRAB)
#define AP_SLOTMEM_IS_PERSIST(t) (t->desc->type & AP_SLOTMEM_TYPE_PERSIST)
#define AP_SLOTMEM_IS_CLEARINUSE(t) (t->desc->type & AP_SLOTMEM_TYPE_CLEARINUSE)
/* The description of the slots to reuse the slotmem */
typedef struct {
apr_size_t size; /* size of each memory slot */
unsigned int num; /* number of mem slots */
ap_slotmem_type_t type; /* type-specific flags */
} sharedslotdesc_t;
#define AP_SLOTMEM_OFFSET (APR_ALIGN_DEFAULT(sizeof(sharedslotdesc_t)))
#define AP_UNSIGNEDINT_OFFSET (APR_ALIGN_DEFAULT(sizeof(unsigned int)))
struct ap_slotmem_instance_t {
char *name; /* file based SHM path/name */
char *pname; /* persisted file path/name */
int fbased; /* filebased? */
void *shm; /* ptr to memory segment (apr_shm_t *) */
void *base; /* data set start */
apr_pool_t *gpool; /* per segment pool (generation cleared) */
char *inuse; /* in-use flag table*/
unsigned int *num_free; /* slot free count for this instance */
void *persist; /* persist dataset start */
const sharedslotdesc_t *desc; /* per slot desc */
struct ap_slotmem_instance_t *next; /* location of next allocated segment */
};
/*
* Layout for SHM and persisted file :
*
* +-------------------------------------------------------------+~>
* | desc | num_free | base (slots) | inuse (array) | md5 | desc | compat..
* +------+-----------------------------------------+------------+~>
* ^ ^ ^ \ / ^ :
* |______|_____________ SHM (mem->@) ______________| | _____|__/
* | |/ |
* | ^ v |
* |_____________________ File (mem->persist + [meta]) __|
*/
/* global pool and list of slotmem we are handling */
static struct ap_slotmem_instance_t *globallistmem = NULL;
static apr_pool_t *gpool = NULL;
#define DEFAULT_SLOTMEM_PREFIX "slotmem-shm-"
#define DEFAULT_SLOTMEM_SUFFIX ".shm"
#define DEFAULT_SLOTMEM_PERSIST_SUFFIX ".persist"
/*
* Persist the slotmem in a file
* slotmem name and file name.
* none : no persistent data
* rel_name : $server_root/rel_name
* /abs_name : $abs_name
*
*/
static int slotmem_filenames(apr_pool_t *pool,
const char *slotname,
const char **filename,
const char **persistname)
{
const char *fname = NULL, *pname = NULL;
if (slotname && *slotname && strcasecmp(slotname, "none") != 0) {
if (slotname[0] != '/') {
/* Each generation needs its own file name. */
int generation = 0;
ap_mpm_query(AP_MPMQ_GENERATION, &generation);
fname = apr_psprintf(pool, "%s%s_%x%s", DEFAULT_SLOTMEM_PREFIX,
slotname, generation, DEFAULT_SLOTMEM_SUFFIX);
fname = ap_runtime_dir_relative(pool, fname);
}
else {
/* Don't mangle the file name if given an absolute path, it's
* up to the caller to provide a unique name when necessary.
*/
fname = slotname;
}
if (persistname) {
/* Persisted file names are immutable... */
if (slotname[0] != '/') {
pname = apr_pstrcat(pool, DEFAULT_SLOTMEM_PREFIX,
slotname, DEFAULT_SLOTMEM_SUFFIX,
DEFAULT_SLOTMEM_PERSIST_SUFFIX,
NULL);
pname = ap_runtime_dir_relative(pool, pname);
}
else {
pname = apr_pstrcat(pool, slotname,
DEFAULT_SLOTMEM_PERSIST_SUFFIX,
NULL);
}
}
}
*filename = fname;
if (persistname) {
*persistname = pname;
}
return (fname != NULL);
}
static void slotmem_clearinuse(ap_slotmem_instance_t *slot)
{
unsigned int i;
char *inuse;
if (!slot) {
return;
}
inuse = slot->inuse;
for (i = 0; i < slot->desc->num; i++, inuse++) {
if (*inuse) {
*inuse = 0;
(*slot->num_free)++;
}
}
}
static void store_slotmem(ap_slotmem_instance_t *slotmem)
{
apr_file_t *fp;
apr_status_t rv;
apr_size_t nbytes;
unsigned char digest[APR_MD5_DIGESTSIZE];
const char *storename = slotmem->pname;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02334)
"storing %s", storename);
if (storename) {
rv = apr_file_open(&fp, storename, APR_CREATE | APR_READ | APR_WRITE,
APR_OS_DEFAULT, slotmem->gpool);
if (APR_STATUS_IS_EEXIST(rv)) {
apr_file_remove(storename, slotmem->gpool);
rv = apr_file_open(&fp, storename, APR_CREATE | APR_READ | APR_WRITE,
APR_OS_DEFAULT, slotmem->gpool);
}
if (rv != APR_SUCCESS) {
return;
}
if (AP_SLOTMEM_IS_CLEARINUSE(slotmem)) {
slotmem_clearinuse(slotmem);
}
nbytes = (slotmem->desc->size * slotmem->desc->num) +
(slotmem->desc->num * sizeof(char)) + AP_UNSIGNEDINT_OFFSET;
apr_md5(digest, slotmem->persist, nbytes);
rv = apr_file_write_full(fp, slotmem->persist, nbytes, NULL);
if (rv == APR_SUCCESS) {
rv = apr_file_write_full(fp, digest, APR_MD5_DIGESTSIZE, NULL);
}
if (rv == APR_SUCCESS) {
rv = apr_file_write_full(fp, slotmem->desc, AP_SLOTMEM_OFFSET,
NULL);
}
apr_file_close(fp);
if (rv != APR_SUCCESS) {
apr_file_remove(storename, slotmem->gpool);
}
}
}
static apr_status_t restore_slotmem(sharedslotdesc_t *desc,
const char *storename, apr_size_t size,
apr_pool_t *pool)
{
apr_file_t *fp;
apr_status_t rv = APR_ENOTIMPL;
void *ptr = (char *)desc + AP_SLOTMEM_OFFSET;
apr_size_t nbytes = size - AP_SLOTMEM_OFFSET;
unsigned char digest[APR_MD5_DIGESTSIZE];
unsigned char digest2[APR_MD5_DIGESTSIZE];
char desc_buf[AP_SLOTMEM_OFFSET];
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02335)
"restoring %s", storename);
if (storename) {
rv = apr_file_open(&fp, storename, APR_READ | APR_WRITE, APR_OS_DEFAULT,
pool);
if (rv == APR_SUCCESS) {
rv = apr_file_read_full(fp, ptr, nbytes, NULL);
if (rv == APR_SUCCESS || rv == APR_EOF) {
/*
* if at EOF, don't bother checking md5
* - backwards compatibility
* */
if (apr_file_eof(fp) != APR_EOF) {
rv = apr_file_read_full(fp, digest, APR_MD5_DIGESTSIZE, NULL);
if (rv == APR_SUCCESS || rv == APR_EOF) {
apr_md5(digest2, ptr, nbytes);
if (memcmp(digest, digest2, APR_MD5_DIGESTSIZE)) {
rv = APR_EMISMATCH;
}
/*
* if at EOF, don't bother checking desc
* - backwards compatibility
* */
else if (apr_file_eof(fp) != APR_EOF) {
rv = apr_file_read_full(fp, desc_buf, sizeof(desc_buf), NULL);
if (rv == APR_SUCCESS || rv == APR_EOF) {
if (memcmp(desc, desc_buf, sizeof(desc_buf))) {
rv = APR_EMISMATCH;
}
else {
rv = APR_SUCCESS;
}
}
else {
rv = APR_INCOMPLETE;
}
}
else {
rv = APR_EOF;
}
}
else {
rv = APR_INCOMPLETE;
}
}
else {
rv = APR_EOF;
}
if (rv == APR_EMISMATCH) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf, APLOGNO(02551)
"persisted slotmem md5/desc mismatch");
}
else if (rv == APR_EOF) {
ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, ap_server_conf, APLOGNO(02552)
"persisted slotmem at EOF... bypassing md5/desc match check "
"(old persist file?)");
rv = APR_SUCCESS;
}
}
else {
rv = APR_INCOMPLETE;
}
if (rv == APR_INCOMPLETE) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf, APLOGNO(02553)
"persisted slotmem read had unexpected size");
}
apr_file_close(fp);
}
}
return rv;
}
/*
* Whether the module is called from a MPM that re-enter main() and
* pre/post_config phases.
*/
static APR_INLINE int is_child_process(void)
{
#ifdef WIN32
return getenv("AP_PARENT_PID") != NULL;
#else
return 0;
#endif
}
static apr_status_t cleanup_slotmem(void *param)
{
int is_child = is_child_process();
ap_slotmem_instance_t *next = globallistmem;
while (next) {
if (!is_child && AP_SLOTMEM_IS_PERSIST(next)) {
store_slotmem(next);
}
apr_shm_destroy(next->shm);
apr_shm_remove(next->name, next->gpool);
next = next->next;
}
globallistmem = NULL;
return APR_SUCCESS;
}
static apr_status_t slotmem_doall(ap_slotmem_instance_t *mem,
ap_slotmem_callback_fn_t *func,
void *data, apr_pool_t *pool)
{
unsigned int i;
char *ptr;
char *inuse;
apr_status_t retval = APR_SUCCESS;
if (!mem) {
return APR_ENOSHMAVAIL;
}
ptr = (char *)mem->base;
inuse = mem->inuse;
for (i = 0; i < mem->desc->num; i++, inuse++) {
if (!AP_SLOTMEM_IS_PREGRAB(mem) || *inuse) {
retval = func((void *) ptr, data, pool);
if (retval != APR_SUCCESS)
break;
}
ptr += mem->desc->size;
}
return retval;
}
static apr_status_t slotmem_create(ap_slotmem_instance_t **new,
const char *name, apr_size_t item_size,
unsigned int item_num,
ap_slotmem_type_t type, apr_pool_t *pool)
{
int fbased = 1;
int restored = 0;
char *ptr;
sharedslotdesc_t *desc;
ap_slotmem_instance_t *res;
ap_slotmem_instance_t *next = globallistmem;
const char *fname, *pname = NULL;
apr_shm_t *shm;
apr_size_t basesize = (item_size * item_num);
apr_size_t size = AP_SLOTMEM_OFFSET + AP_UNSIGNEDINT_OFFSET +
(item_num * sizeof(char)) + basesize;
int persist = (type & AP_SLOTMEM_TYPE_PERSIST) != 0;
apr_status_t rv;
*new = NULL;
if (gpool == NULL) {
return APR_ENOSHMAVAIL;
}
if (slotmem_filenames(pool, name, &fname, persist ? &pname : NULL)) {
/* first try to attach to existing slotmem */
if (next) {
for (;;) {
if (strcmp(next->name, fname) == 0) {
/* we already have it */
*new = next;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02603)
"create found %s in global list", fname);
return APR_SUCCESS;
}
if (!next->next) {
break;
}
next = next->next;
}
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02602)
"create didn't find %s in global list", fname);
}
else {
fbased = 0;
fname = "none";
}
/* first try to attach to existing shared memory */
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02300)
"create %s: %"APR_SIZE_T_FMT"/%u", fname, item_size,
item_num);
{
/* For MPMs that run pre/post_config() phases in both the parent
* and children processes (e.g. winnt), SHMs created by the
* parent exist in the children already; attach them.
*/
if (fbased) {
if (is_child_process()) {
rv = apr_shm_attach(&shm, fname, gpool);
}
else {
apr_shm_remove(fname, pool);
rv = apr_shm_create(&shm, size, fname, gpool);
}
}
else {
rv = apr_shm_create(&shm, size, NULL, gpool);
}
ap_log_error(APLOG_MARK, rv == APR_SUCCESS ? APLOG_DEBUG : APLOG_ERR,
rv, ap_server_conf, APLOGNO(02611)
"create: apr_shm_%s(%s) %s",
fbased && is_child_process() ? "attach" : "create",
fname, rv == APR_SUCCESS ? "succeeded" : "failed");
if (rv != APR_SUCCESS) {
return rv;
}
desc = (sharedslotdesc_t *)apr_shm_baseaddr_get(shm);
memset(desc, 0, size);
desc->size = item_size;
desc->num = item_num;
desc->type = type;
/*
* TODO: Error check the below... What error makes
* sense if the restore fails? Any?
* For now, we continue with a fresh new slotmem,
* but NOTICE in the log.
*/
if (persist) {
rv = restore_slotmem(desc, pname, size, pool);
if (rv == APR_SUCCESS) {
restored = 1;
}
else {
/* just in case, re-zero */
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
APLOGNO(02554) "could not restore %s", fname);
memset((char *)desc + AP_SLOTMEM_OFFSET, 0,
size - AP_SLOTMEM_OFFSET);
}
}
}
ptr = (char *)desc + AP_SLOTMEM_OFFSET;
/* For the chained slotmem stuff */
res = apr_pcalloc(gpool, sizeof(ap_slotmem_instance_t));
res->name = apr_pstrdup(gpool, fname);
res->pname = apr_pstrdup(gpool, pname);
res->fbased = fbased;
res->shm = shm;
res->persist = (void *)ptr;
res->num_free = (unsigned int *)ptr;
ptr += AP_UNSIGNEDINT_OFFSET;
if (!restored) {
*res->num_free = item_num;
}
res->base = (void *)ptr;
res->desc = desc;
res->gpool = gpool;
res->next = NULL;
res->inuse = ptr + basesize;
if (fbased) {
if (globallistmem == NULL) {
globallistmem = res;
}
else {
next->next = res;
}
}
*new = res;
return APR_SUCCESS;
}
static apr_status_t slotmem_attach(ap_slotmem_instance_t **new,
const char *name, apr_size_t *item_size,
unsigned int *item_num, apr_pool_t *pool)
{
char *ptr;
ap_slotmem_instance_t *res;
ap_slotmem_instance_t *next = globallistmem;
sharedslotdesc_t *desc;
const char *fname;
apr_shm_t *shm;
apr_status_t rv;
if (gpool == NULL) {
return APR_ENOSHMAVAIL;
}
if (!slotmem_filenames(pool, name, &fname, NULL)) {
return APR_ENOSHMAVAIL;
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02301)
"attach looking for %s", fname);
/* first try to attach to existing slotmem */
if (next) {
for (;;) {
if (strcmp(next->name, fname) == 0) {
/* we already have it */
*new = next;
*item_size = next->desc->size;
*item_num = next->desc->num;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
APLOGNO(02302)
"attach found %s: %"APR_SIZE_T_FMT"/%u", fname,
*item_size, *item_num);
return APR_SUCCESS;
}
if (!next->next) {
break;
}
next = next->next;
}
}
/* next try to attach to existing shared memory */
rv = apr_shm_attach(&shm, fname, gpool);
if (rv != APR_SUCCESS) {
return rv;
}
/* Read the description of the slotmem */
desc = (sharedslotdesc_t *)apr_shm_baseaddr_get(shm);
ptr = (char *)desc + AP_SLOTMEM_OFFSET;
/* For the chained slotmem stuff */
res = apr_pcalloc(gpool, sizeof(ap_slotmem_instance_t));
res->name = apr_pstrdup(gpool, fname);
res->fbased = 1;
res->shm = shm;
res->persist = (void *)ptr;
res->num_free = (unsigned int *)ptr;
ptr += AP_UNSIGNEDINT_OFFSET;
res->base = (void *)ptr;
res->desc = desc;
res->gpool = gpool;
res->inuse = ptr + (desc->size * desc->num);
res->next = NULL;
*new = res;
*item_size = desc->size;
*item_num = desc->num;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf,
APLOGNO(02303)
"attach found %s: %"APR_SIZE_T_FMT"/%u", fname,
*item_size, *item_num);
return APR_SUCCESS;
}
static apr_status_t slotmem_dptr(ap_slotmem_instance_t *slot,
unsigned int id, void **mem)
{
char *ptr;
if (!slot) {
return APR_ENOSHMAVAIL;
}
if (id >= slot->desc->num) {
return APR_EINVAL;
}
ptr = (char *)slot->base + slot->desc->size * id;
if (!ptr) {
return APR_ENOSHMAVAIL;
}
*mem = (void *)ptr;
return APR_SUCCESS;
}
static apr_status_t slotmem_get(ap_slotmem_instance_t *slot, unsigned int id,
unsigned char *dest, apr_size_t dest_len)
{
void *ptr;
char *inuse;
apr_status_t ret;
if (!slot) {
return APR_ENOSHMAVAIL;
}
inuse = slot->inuse + id;
if (id >= slot->desc->num) {
return APR_EINVAL;
}
if (AP_SLOTMEM_IS_PREGRAB(slot) && !*inuse) {
return APR_NOTFOUND;
}
ret = slotmem_dptr(slot, id, &ptr);
if (ret != APR_SUCCESS) {
return ret;
}
*inuse = 1;
memcpy(dest, ptr, dest_len); /* bounds check? */
return APR_SUCCESS;
}
static apr_status_t slotmem_put(ap_slotmem_instance_t *slot, unsigned int id,
unsigned char *src, apr_size_t src_len)
{
void *ptr;
char *inuse;
apr_status_t ret;
if (!slot) {
return APR_ENOSHMAVAIL;
}
inuse = slot->inuse + id;
if (id >= slot->desc->num) {
return APR_EINVAL;
}
if (AP_SLOTMEM_IS_PREGRAB(slot) && !*inuse) {
return APR_NOTFOUND;
}
ret = slotmem_dptr(slot, id, &ptr);
if (ret != APR_SUCCESS) {
return ret;
}
*inuse=1;
memcpy(ptr, src, src_len); /* bounds check? */
return APR_SUCCESS;
}
static unsigned int slotmem_num_slots(ap_slotmem_instance_t *slot)
{
return slot->desc->num;
}
static unsigned int slotmem_num_free_slots(ap_slotmem_instance_t *slot)
{
if (AP_SLOTMEM_IS_PREGRAB(slot))
return *slot->num_free;
else {
unsigned int i, counter=0;
char *inuse = slot->inuse;
for (i=0; i<slot->desc->num; i++, inuse++) {
if (!*inuse)
counter++;
}
return counter;
}
}
static apr_size_t slotmem_slot_size(ap_slotmem_instance_t *slot)
{
return slot->desc->size;
}
static apr_status_t slotmem_grab(ap_slotmem_instance_t *slot, unsigned int *id)
{
unsigned int i;
char *inuse;
if (!slot) {
return APR_ENOSHMAVAIL;
}
inuse = slot->inuse;
for (i = 0; i < slot->desc->num; i++, inuse++) {
if (!*inuse) {
break;
}
}
if (i >= slot->desc->num) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02293)
"slotmem(%s) grab failed. Num %u/num_free %u",
slot->name, slotmem_num_slots(slot),
slotmem_num_free_slots(slot));
return APR_EINVAL;
}
*inuse = 1;
*id = i;
(*slot->num_free)--;
return APR_SUCCESS;
}
static apr_status_t slotmem_fgrab(ap_slotmem_instance_t *slot, unsigned int id)
{
char *inuse;
if (!slot) {
return APR_ENOSHMAVAIL;
}
if (id >= slot->desc->num) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02397)
"slotmem(%s) fgrab failed. Num %u/num_free %u",
slot->name, slotmem_num_slots(slot),
slotmem_num_free_slots(slot));
return APR_EINVAL;
}
inuse = slot->inuse + id;
if (!*inuse) {
*inuse = 1;
(*slot->num_free)--;
}
return APR_SUCCESS;
}
static apr_status_t slotmem_release(ap_slotmem_instance_t *slot,
unsigned int id)
{
char *inuse;
if (!slot) {
return APR_ENOSHMAVAIL;
}
inuse = slot->inuse;
if (id >= slot->desc->num || !inuse[id] ) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, ap_server_conf, APLOGNO(02294)
"slotmem(%s) release failed. Num %u/inuse[%u] %d",
slot->name, slotmem_num_slots(slot),
id, (int)inuse[id]);
if (id >= slot->desc->num) {
return APR_EINVAL;
} else {
return APR_NOTFOUND;
}
}
inuse[id] = 0;
(*slot->num_free)++;
return APR_SUCCESS;
}
static const ap_slotmem_provider_t storage = {
"sharedmem",
&slotmem_doall,
&slotmem_create,
&slotmem_attach,
&slotmem_dptr,
&slotmem_get,
&slotmem_put,
&slotmem_num_slots,
&slotmem_num_free_slots,
&slotmem_slot_size,
&slotmem_grab,
&slotmem_release,
&slotmem_fgrab
};
/* make the storage usable from outside */
static const ap_slotmem_provider_t *slotmem_shm_getstorage(void)
{
return (&storage);
}
/*
* Make sure the shared memory is cleaned
*/
static int post_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp,
server_rec *s)
{
apr_pool_cleanup_register(p, NULL, cleanup_slotmem, apr_pool_cleanup_null);
return OK;
}
static int pre_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp)
{
gpool = p;
globallistmem = NULL;
return OK;
}
static void ap_slotmem_shm_register_hook(apr_pool_t *p)
{
const ap_slotmem_provider_t *storage = slotmem_shm_getstorage();
ap_register_provider(p, AP_SLOTMEM_PROVIDER_GROUP, "shm",
AP_SLOTMEM_PROVIDER_VERSION, storage);
ap_hook_post_config(post_config, NULL, NULL, APR_HOOK_LAST);
ap_hook_pre_config(pre_config, NULL, NULL, APR_HOOK_MIDDLE);
}
AP_DECLARE_MODULE(slotmem_shm) = {
STANDARD20_MODULE_STUFF,
NULL, /* create per-directory config structure */
NULL, /* merge per-directory config structures */
NULL, /* create per-server config structure */
NULL, /* merge per-server config structures */
NULL, /* command apr_table_t */
ap_slotmem_shm_register_hook /* register hooks */
};