diff options
Diffstat (limited to 'shmem/win32/shm.c')
| -rw-r--r-- | shmem/win32/shm.c | 452 |
1 files changed, 452 insertions, 0 deletions
diff --git a/shmem/win32/shm.c b/shmem/win32/shm.c new file mode 100644 index 0000000..8d8848e --- /dev/null +++ b/shmem/win32/shm.c @@ -0,0 +1,452 @@ +/* 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; +} + |