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-rw-r--r--shmem/win32/shm.c452
1 files changed, 452 insertions, 0 deletions
diff --git a/shmem/win32/shm.c b/shmem/win32/shm.c
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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 "apr_general.h"
+#include "apr_errno.h"
+#include "apr_file_io.h"
+#include "apr_shm.h"
+#include "apr_strings.h"
+#include "apr_arch_file_io.h"
+#include "limits.h"
+
+typedef struct memblock_t {
+ apr_size_t size;
+ apr_size_t length;
+} memblock_t;
+
+struct apr_shm_t {
+ apr_pool_t *pool;
+ memblock_t *memblk;
+ void *usrmem;
+ apr_size_t size;
+ apr_size_t length;
+ HANDLE hMap;
+ const char *filename;
+};
+
+static apr_status_t shm_cleanup(void* shm)
+{
+ apr_status_t rv = APR_SUCCESS;
+ apr_shm_t *m = shm;
+
+ if (!UnmapViewOfFile(m->memblk)) {
+ rv = apr_get_os_error();
+ }
+ if (!CloseHandle(m->hMap)) {
+ rv = rv != APR_SUCCESS ? rv : apr_get_os_error();
+ }
+ if (m->filename) {
+ /* Remove file if file backed */
+ apr_status_t rc = apr_file_remove(m->filename, m->pool);
+ rv = rv != APR_SUCCESS ? rv : rc;
+ }
+ return rv;
+}
+
+/* See if the caller is able to create a map in the global namespace by
+ * checking if the SE_CREATE_GLOBAL_NAME privilege is enabled.
+ *
+ * Prior to APR 1.5.0, named shared memory segments were always created
+ * in the global segment. However, with recent versions of Windows this
+ * fails for unprivileged processes. Thus, with older APR, named shared
+ * memory segments can't be created by unprivileged processes on newer
+ * Windows.
+ *
+ * By checking if the caller has the privilege, shm APIs can decide
+ * whether to use the Global or Local namespace.
+ *
+ * If running on an SDK without the required API definitions *OR*
+ * some processing failure occurs trying to check the privilege, fall
+ * back to earlier behavior -- always try to use the Global namespace.
+ */
+#ifdef SE_CREATE_GLOBAL_NAME
+static int can_create_global_maps(void)
+{
+ BOOL ok, has_priv;
+ LUID priv_id;
+ PRIVILEGE_SET privs;
+ HANDLE hToken;
+
+ ok = OpenThreadToken(GetCurrentThread(), TOKEN_QUERY, TRUE, &hToken);
+ if (!ok && GetLastError() == ERROR_NO_TOKEN) {
+ /* no thread-specific access token, so try to get process access token
+ */
+ ok = OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &hToken);
+ }
+
+ if (ok) {
+ ok = LookupPrivilegeValue(NULL, SE_CREATE_GLOBAL_NAME, &priv_id);
+ }
+
+ if (ok) {
+ privs.PrivilegeCount = 1;
+ privs.Control = PRIVILEGE_SET_ALL_NECESSARY;
+ privs.Privilege[0].Luid = priv_id;
+ privs.Privilege[0].Attributes = SE_PRIVILEGE_ENABLED;
+ ok = PrivilegeCheck(hToken, &privs, &has_priv);
+ }
+
+ if (ok && !has_priv) {
+ return 0;
+ }
+ else {
+ return 1;
+ }
+}
+#else /* SE_CREATE_GLOBAL_NAME */
+/* SDK definitions missing */
+static int can_create_global_maps(void)
+{
+ return 1;
+}
+#endif /* SE_CREATE_GLOBAL_NAME */
+
+APR_DECLARE(apr_status_t) apr_shm_create_ex(apr_shm_t **m,
+ apr_size_t reqsize,
+ const char *file,
+ apr_pool_t *pool,
+ apr_int32_t flags)
+{
+ static apr_size_t memblock = 0;
+ HANDLE hMap, hFile;
+ apr_status_t rv;
+ apr_size_t size;
+ apr_file_t *f;
+ void *base;
+ void *mapkey;
+ DWORD err, sizelo, sizehi;
+
+ reqsize += sizeof(memblock_t);
+
+ if (!memblock)
+ {
+ SYSTEM_INFO si;
+ GetSystemInfo(&si);
+ memblock = si.dwAllocationGranularity;
+ }
+
+ /* Compute the granualar multiple of the pagesize */
+ size = memblock * (1 + (reqsize - 1) / memblock);
+ sizelo = (DWORD)size;
+#ifdef _WIN64
+ sizehi = (DWORD)(size >> 32);
+#else
+ sizehi = 0;
+#endif
+
+ if (!file) {
+ /* Do Anonymous, which must be passed as a duplicated handle */
+#ifndef _WIN32_WCE
+ hFile = INVALID_HANDLE_VALUE;
+#endif
+ mapkey = NULL;
+ }
+ else {
+ int global;
+
+ /* Do file backed, which is not an inherited handle
+ * While we could open APR_EXCL, it doesn't seem that Unix
+ * ever did. Ignore that error here, but fail later when
+ * we discover we aren't the creator of the file map object.
+ */
+ rv = apr_file_open(&f, file,
+ APR_READ | APR_WRITE | APR_BINARY | APR_CREATE,
+ APR_UREAD | APR_UWRITE, pool);
+ if ((rv != APR_SUCCESS)
+ || ((rv = apr_os_file_get(&hFile, f)) != APR_SUCCESS)) {
+ return rv;
+ }
+ rv = apr_file_trunc(f, size);
+
+ /* res_name_from_filename turns file into a pseudo-name
+ * without slashes or backslashes, and prepends the \global
+ * or \local prefix on Win2K and later
+ */
+ if (flags & APR_SHM_NS_GLOBAL) {
+ global = 1;
+ }
+ else if (flags & APR_SHM_NS_LOCAL) {
+ global = 0;
+ }
+ else {
+ global = can_create_global_maps();
+ }
+ mapkey = res_name_from_filename(file, global, pool);
+ }
+
+#if APR_HAS_UNICODE_FS
+ IF_WIN_OS_IS_UNICODE
+ {
+ hMap = CreateFileMappingW(hFile, NULL, PAGE_READWRITE,
+ sizehi, sizelo, mapkey);
+ }
+#endif
+#if APR_HAS_ANSI_FS
+ ELSE_WIN_OS_IS_ANSI
+ {
+ hMap = CreateFileMappingA(hFile, NULL, PAGE_READWRITE,
+ sizehi, sizelo, mapkey);
+ }
+#endif
+ err = apr_get_os_error();
+
+ if (file) {
+ apr_file_close(f);
+ }
+
+ if (hMap && APR_STATUS_IS_EEXIST(err)) {
+ CloseHandle(hMap);
+ return APR_EEXIST;
+ }
+ if (!hMap) {
+ return err;
+ }
+
+ base = MapViewOfFile(hMap, FILE_MAP_READ | FILE_MAP_WRITE,
+ 0, 0, size);
+ if (!base) {
+ CloseHandle(hMap);
+ return apr_get_os_error();
+ }
+
+ *m = (apr_shm_t *) apr_palloc(pool, sizeof(apr_shm_t));
+ (*m)->pool = pool;
+ (*m)->hMap = hMap;
+ (*m)->memblk = base;
+ (*m)->size = size;
+
+ (*m)->usrmem = (char*)base + sizeof(memblock_t);
+ (*m)->length = reqsize - sizeof(memblock_t);;
+
+ (*m)->memblk->length = (*m)->length;
+ (*m)->memblk->size = (*m)->size;
+ (*m)->filename = file ? apr_pstrdup(pool, file) : NULL;
+
+ apr_pool_cleanup_register((*m)->pool, *m,
+ shm_cleanup, apr_pool_cleanup_null);
+ return APR_SUCCESS;
+}
+
+APR_DECLARE(apr_status_t) apr_shm_create(apr_shm_t **m,
+ apr_size_t reqsize,
+ const char *file,
+ apr_pool_t *pool)
+{
+ return apr_shm_create_ex(m, reqsize, file, pool, 0);
+}
+
+APR_DECLARE(apr_status_t) apr_shm_destroy(apr_shm_t *m)
+{
+ apr_status_t rv = shm_cleanup(m);
+ apr_pool_cleanup_kill(m->pool, m, shm_cleanup);
+ return rv;
+}
+
+APR_DECLARE(apr_status_t) apr_shm_remove(const char *filename,
+ apr_pool_t *pool)
+{
+ return apr_file_remove(filename, pool);
+}
+
+APR_DECLARE(apr_status_t) apr_shm_delete(apr_shm_t *m)
+{
+ if (m->filename) {
+ return apr_shm_remove(m->filename, m->pool);
+ }
+ else {
+ return APR_ENOTIMPL;
+ }
+}
+
+static apr_status_t shm_attach_internal(apr_shm_t **m,
+ const char *file,
+ apr_pool_t *pool,
+ int global)
+{
+ HANDLE hMap;
+ void *mapkey;
+ void *base;
+
+ /* res_name_from_filename turns file into a pseudo-name
+ * without slashes or backslashes, and prepends the \global
+ * or local prefix on Win2K and later
+ */
+ mapkey = res_name_from_filename(file, global, pool);
+
+#if APR_HAS_UNICODE_FS
+ IF_WIN_OS_IS_UNICODE
+ {
+#ifndef _WIN32_WCE
+ hMap = OpenFileMappingW(FILE_MAP_READ | FILE_MAP_WRITE, FALSE, mapkey);
+#else
+ /* The WCE 3.0 lacks OpenFileMapping. So we emulate one with
+ * opening the existing shmem and reading its size from the header
+ */
+ hMap = CreateFileMappingW(INVALID_HANDLE_VALUE, NULL,
+ PAGE_READWRITE, 0, sizeof(apr_shm_t), mapkey);
+#endif
+ }
+#endif
+#if APR_HAS_ANSI_FS
+ ELSE_WIN_OS_IS_ANSI
+ {
+ hMap = OpenFileMappingA(FILE_MAP_READ | FILE_MAP_WRITE, FALSE, mapkey);
+ }
+#endif
+
+ if (!hMap) {
+ return apr_get_os_error();
+ }
+
+ base = MapViewOfFile(hMap, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0);
+ if (!base) {
+ CloseHandle(hMap);
+ return apr_get_os_error();
+ }
+
+ *m = (apr_shm_t *) apr_palloc(pool, sizeof(apr_shm_t));
+ (*m)->pool = pool;
+ (*m)->memblk = base;
+ /* Real (*m)->mem->size could be recovered with VirtualQuery */
+ (*m)->size = (*m)->memblk->size;
+#if _WIN32_WCE
+ /* Reopen with real size */
+ UnmapViewOfFile(base);
+ CloseHandle(hMap);
+
+ hMap = CreateFileMappingW(INVALID_HANDLE_VALUE, NULL,
+ PAGE_READWRITE, 0, (*m)->size, mapkey);
+ if (!hMap) {
+ return apr_get_os_error();
+ }
+ base = MapViewOfFile(hMap, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0);
+ if (!base) {
+ CloseHandle(hMap);
+ return apr_get_os_error();
+ }
+#endif
+ (*m)->hMap = hMap;
+ (*m)->length = (*m)->memblk->length;
+ (*m)->usrmem = (char*)base + sizeof(memblock_t);
+ (*m)->filename = NULL;
+
+ apr_pool_cleanup_register((*m)->pool, *m,
+ shm_cleanup, apr_pool_cleanup_null);
+ return APR_SUCCESS;
+}
+
+APR_DECLARE(apr_status_t) apr_shm_attach_ex(apr_shm_t **m,
+ const char *file,
+ apr_pool_t *pool,
+ apr_int32_t flags)
+{
+ apr_status_t rv;
+ int can_create_global;
+ int try_global_local[3] = {-1, -1, -1};
+ int cur;
+
+ if (!file) {
+ return APR_EINVAL;
+ }
+
+ if (flags & APR_SHM_NS_LOCAL) {
+ try_global_local[0] = 0; /* only search local */
+ }
+ else if (flags & APR_SHM_NS_GLOBAL) {
+ try_global_local[0] = 1; /* only search global */
+ }
+ else {
+ can_create_global = can_create_global_maps();
+ if (!can_create_global) { /* unprivileged process */
+ try_global_local[0] = 0; /* search local before global */
+ try_global_local[1] = 1;
+ }
+ else {
+ try_global_local[0] = 1; /* search global before local */
+ try_global_local[1] = 0;
+ }
+ }
+
+ for (cur = 0; try_global_local[cur] != -1; cur++) {
+ rv = shm_attach_internal(m, file, pool, try_global_local[cur]);
+ if (!APR_STATUS_IS_ENOENT(rv)) {
+ break;
+ }
+ }
+
+ return rv;
+}
+
+APR_DECLARE(apr_status_t) apr_shm_attach(apr_shm_t **m,
+ const char *file,
+ apr_pool_t *pool)
+{
+ return apr_shm_attach_ex(m, file, pool, 0);
+}
+
+APR_DECLARE(apr_status_t) apr_shm_detach(apr_shm_t *m)
+{
+ apr_status_t rv = shm_cleanup(m);
+ apr_pool_cleanup_kill(m->pool, m, shm_cleanup);
+ return rv;
+}
+
+APR_DECLARE(void *) apr_shm_baseaddr_get(const apr_shm_t *m)
+{
+ return m->usrmem;
+}
+
+APR_DECLARE(apr_size_t) apr_shm_size_get(const apr_shm_t *m)
+{
+ return m->length;
+}
+
+APR_PERMS_SET_ENOTIMPL(shm)
+
+APR_POOL_IMPLEMENT_ACCESSOR(shm)
+
+APR_DECLARE(apr_status_t) apr_os_shm_get(apr_os_shm_t *osshm,
+ apr_shm_t *shm)
+{
+ *osshm = shm->hMap;
+ return APR_SUCCESS;
+}
+
+APR_DECLARE(apr_status_t) apr_os_shm_put(apr_shm_t **m,
+ apr_os_shm_t *osshm,
+ apr_pool_t *pool)
+{
+ void* base;
+ base = MapViewOfFile(*osshm, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0);
+ if (!base) {
+ return apr_get_os_error();
+ }
+
+ *m = (apr_shm_t *) apr_palloc(pool, sizeof(apr_shm_t));
+ (*m)->pool = pool;
+ (*m)->hMap = *osshm;
+ (*m)->memblk = base;
+ (*m)->usrmem = (char*)base + sizeof(memblock_t);
+ /* Real (*m)->mem->size could be recovered with VirtualQuery */
+ (*m)->size = (*m)->memblk->size;
+ (*m)->length = (*m)->memblk->length;
+ (*m)->filename = NULL;
+
+ apr_pool_cleanup_register((*m)->pool, *m,
+ shm_cleanup, apr_pool_cleanup_null);
+ return APR_SUCCESS;
+}
+