1/* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements.  See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License.  You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "apr.h"
18#include "apr_private.h"
19#include "apr_general.h"
20#include "apr_mmap.h"
21#include "apr_errno.h"
22#include "apr_arch_file_io.h"
23#include "apr_portable.h"
24#include "apr_strings.h"
25
26#if APR_HAS_MMAP
27
28static apr_status_t mmap_cleanup(void *themmap)
29{
30    apr_mmap_t *mm = themmap;
31    apr_mmap_t *next = APR_RING_NEXT(mm,link);
32
33    /* we no longer refer to the mmaped region */
34    APR_RING_REMOVE(mm,link);
35    APR_RING_NEXT(mm,link) = NULL;
36    APR_RING_PREV(mm,link) = NULL;
37
38    if (next != mm) {
39        /* more references exist, so we're done */
40        return APR_SUCCESS;
41    }
42
43    if (mm->mv) {
44        if (!UnmapViewOfFile(mm->mv))
45        {
46            apr_status_t rv = apr_get_os_error();
47            CloseHandle(mm->mhandle);
48            mm->mv = NULL;
49            mm->mhandle = NULL;
50            return rv;
51        }
52        mm->mv = NULL;
53    }
54    if (mm->mhandle)
55    {
56        if (!CloseHandle(mm->mhandle))
57        {
58            apr_status_t rv = apr_get_os_error();
59            CloseHandle(mm->mhandle);
60            mm->mhandle = NULL;
61            return rv;
62        }
63        mm->mhandle = NULL;
64    }
65    return APR_SUCCESS;
66}
67
68APR_DECLARE(apr_status_t) apr_mmap_create(apr_mmap_t **new, apr_file_t *file,
69                                          apr_off_t offset, apr_size_t size,
70                                          apr_int32_t flag, apr_pool_t *cont)
71{
72    static DWORD memblock = 0;
73    DWORD fmaccess = 0;
74    DWORD mvaccess = 0;
75    DWORD offlo;
76    DWORD offhi;
77
78    if (size == 0)
79        return APR_EINVAL;
80
81    if (flag & APR_MMAP_WRITE)
82        fmaccess |= PAGE_READWRITE;
83    else if (flag & APR_MMAP_READ)
84        fmaccess |= PAGE_READONLY;
85
86    if (flag & APR_MMAP_READ)
87        mvaccess |= FILE_MAP_READ;
88    if (flag & APR_MMAP_WRITE)
89        mvaccess |= FILE_MAP_WRITE;
90
91    if (!file || !file->filehand || file->filehand == INVALID_HANDLE_VALUE
92        || file->buffered)
93        return APR_EBADF;
94
95    if (!memblock)
96    {
97        SYSTEM_INFO si;
98        GetSystemInfo(&si);
99        memblock = si.dwAllocationGranularity;
100    }
101
102    *new = apr_pcalloc(cont, sizeof(apr_mmap_t));
103    (*new)->pstart = (offset / memblock) * memblock;
104    (*new)->poffset = offset - (*new)->pstart;
105    (*new)->psize = (apr_size_t)((*new)->poffset) + size;
106    /* The size of the CreateFileMapping object is the current size
107     * of the size of the mmap object (e.g. file size), not the size
108     * of the mapped region!
109     */
110
111    (*new)->mhandle = CreateFileMapping(file->filehand, NULL, fmaccess,
112                                        0, 0, NULL);
113    if (!(*new)->mhandle || (*new)->mhandle == INVALID_HANDLE_VALUE)
114    {
115        *new = NULL;
116        return apr_get_os_error();
117    }
118
119    offlo = (DWORD)(*new)->pstart;
120    offhi = (DWORD)((*new)->pstart >> 32);
121    (*new)->mv = MapViewOfFile((*new)->mhandle, mvaccess, offhi,
122                               offlo, (*new)->psize);
123    if (!(*new)->mv)
124    {
125        apr_status_t rv = apr_get_os_error();
126        CloseHandle((*new)->mhandle);
127        *new = NULL;
128        return rv;
129    }
130
131    (*new)->mm = (char*)((*new)->mv) + (*new)->poffset;
132    (*new)->size = size;
133    (*new)->cntxt = cont;
134    APR_RING_ELEM_INIT(*new, link);
135
136    /* register the cleanup... */
137    apr_pool_cleanup_register((*new)->cntxt, (void*)(*new), mmap_cleanup,
138                         apr_pool_cleanup_null);
139    return APR_SUCCESS;
140}
141
142APR_DECLARE(apr_status_t) apr_mmap_dup(apr_mmap_t **new_mmap,
143                                       apr_mmap_t *old_mmap,
144                                       apr_pool_t *p)
145{
146    *new_mmap = (apr_mmap_t *)apr_pmemdup(p, old_mmap, sizeof(apr_mmap_t));
147    (*new_mmap)->cntxt = p;
148
149    APR_RING_INSERT_AFTER(old_mmap, *new_mmap, link);
150
151    apr_pool_cleanup_register(p, *new_mmap, mmap_cleanup,
152                              apr_pool_cleanup_null);
153    return APR_SUCCESS;
154}
155
156APR_DECLARE(apr_status_t) apr_mmap_delete(apr_mmap_t *mm)
157{
158    return apr_pool_cleanup_run(mm->cntxt, mm, mmap_cleanup);
159}
160
161#endif
162