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3719602c PC |
1 | /* Copyright (C) 2010-2020 The RetroArch team |
2 | * | |
3 | * --------------------------------------------------------------------------------------- | |
4 | * The following license statement only applies to this file (nbio_unixmmap.c). | |
5 | * --------------------------------------------------------------------------------------- | |
6 | * | |
7 | * Permission is hereby granted, free of charge, | |
8 | * to any person obtaining a copy of this software and associated documentation files (the "Software"), | |
9 | * to deal in the Software without restriction, including without limitation the rights to | |
10 | * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
11 | * and to permit persons to whom the Software is furnished to do so, subject to the following conditions: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. | |
14 | * | |
15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, | |
16 | * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. | |
18 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, | |
19 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
20 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. | |
21 | */ | |
22 | ||
23 | #include <stdio.h> | |
24 | #include <stdlib.h> | |
25 | ||
26 | #ifdef HAVE_CONFIG_H | |
27 | #include "config.h" | |
28 | #endif | |
29 | ||
30 | #include <file/nbio.h> | |
31 | ||
32 | #if defined(HAVE_MMAP) && defined(BSD) | |
33 | ||
34 | #ifdef _WIN32 | |
35 | #include <direct.h> | |
36 | #else | |
37 | #include <unistd.h> | |
38 | #endif | |
39 | #include <fcntl.h> | |
40 | #include <sys/mman.h> | |
41 | ||
42 | #ifdef __APPLE__ | |
43 | ||
44 | #ifndef O_CLOEXEC | |
45 | #define O_CLOEXEC 0x1000000 | |
46 | #endif | |
47 | ||
48 | #else | |
49 | ||
50 | #ifndef O_CLOEXEC | |
51 | #define O_CLOEXEC 0 | |
52 | #endif | |
53 | ||
54 | #endif | |
55 | ||
56 | struct nbio_mmap_unix_t | |
57 | { | |
58 | void* ptr; | |
59 | size_t len; | |
60 | int fd; | |
61 | int map_flags; | |
62 | }; | |
63 | ||
64 | static void *nbio_mmap_unix_open(const char * filename, unsigned mode) | |
65 | { | |
66 | static const int o_flags[] = { O_RDONLY, O_RDWR|O_CREAT|O_TRUNC, O_RDWR, O_RDONLY, O_RDWR|O_CREAT|O_TRUNC }; | |
67 | static const int map_flags[] = { PROT_READ, PROT_WRITE|PROT_READ, PROT_WRITE|PROT_READ, PROT_READ, PROT_WRITE|PROT_READ }; | |
68 | ||
69 | size_t len; | |
70 | void* ptr = NULL; | |
71 | struct nbio_mmap_unix_t* handle = NULL; | |
72 | int fd = open(filename, o_flags[mode]|O_CLOEXEC, 0644); | |
73 | if (fd < 0) | |
74 | return NULL; | |
75 | ||
76 | len = lseek(fd, 0, SEEK_END); | |
77 | if (len != 0) | |
78 | ptr = mmap(NULL, len, map_flags[mode], MAP_SHARED, fd, 0); | |
79 | ||
80 | if (ptr == MAP_FAILED) | |
81 | { | |
82 | close(fd); | |
83 | return NULL; | |
84 | } | |
85 | ||
86 | handle = malloc(sizeof(struct nbio_mmap_unix_t)); | |
87 | handle->fd = fd; | |
88 | handle->map_flags = map_flags[mode]; | |
89 | handle->len = len; | |
90 | handle->ptr = ptr; | |
91 | return handle; | |
92 | } | |
93 | ||
94 | static void nbio_mmap_unix_begin_read(void *data) | |
95 | { | |
96 | /* not needed */ | |
97 | } | |
98 | ||
99 | static void nbio_mmap_unix_begin_write(void *data) | |
100 | { | |
101 | /* not needed */ | |
102 | } | |
103 | ||
104 | static bool nbio_mmap_unix_iterate(void *data) | |
105 | { | |
106 | return true; /* not needed */ | |
107 | } | |
108 | ||
109 | static void nbio_mmap_unix_resize(void *data, size_t len) | |
110 | { | |
111 | struct nbio_mmap_unix_t* handle = (struct nbio_mmap_unix_t*)data; | |
112 | if (!handle) | |
113 | return; | |
114 | if (len < handle->len) | |
115 | { | |
116 | /* this works perfectly fine if this check is removed, but it | |
117 | * won't work on other nbio implementations */ | |
118 | /* therefore, it's blocked so nobody accidentally relies on it */ | |
119 | abort(); | |
120 | } | |
121 | ||
122 | if (ftruncate(handle->fd, len) != 0) | |
123 | abort(); /* this one returns void and I can't find any other | |
124 | way for it to report failure */ | |
125 | ||
126 | munmap(handle->ptr, handle->len); | |
127 | ||
128 | handle->ptr = mmap(NULL, len, handle->map_flags, MAP_SHARED, handle->fd, 0); | |
129 | handle->len = len; | |
130 | ||
131 | if (handle->ptr == MAP_FAILED) | |
132 | abort(); | |
133 | } | |
134 | ||
135 | static void *nbio_mmap_unix_get_ptr(void *data, size_t* len) | |
136 | { | |
137 | struct nbio_mmap_unix_t* handle = (struct nbio_mmap_unix_t*)data; | |
138 | if (!handle) | |
139 | return NULL; | |
140 | if (len) | |
141 | *len = handle->len; | |
142 | return handle->ptr; | |
143 | } | |
144 | ||
145 | static void nbio_mmap_unix_cancel(void *data) | |
146 | { | |
147 | /* not needed */ | |
148 | } | |
149 | ||
150 | static void nbio_mmap_unix_free(void *data) | |
151 | { | |
152 | struct nbio_mmap_unix_t* handle = (struct nbio_mmap_unix_t*)data; | |
153 | if (!handle) | |
154 | return; | |
155 | close(handle->fd); | |
156 | munmap(handle->ptr, handle->len); | |
157 | free(handle); | |
158 | } | |
159 | ||
160 | nbio_intf_t nbio_mmap_unix = { | |
161 | nbio_mmap_unix_open, | |
162 | nbio_mmap_unix_begin_read, | |
163 | nbio_mmap_unix_begin_write, | |
164 | nbio_mmap_unix_iterate, | |
165 | nbio_mmap_unix_resize, | |
166 | nbio_mmap_unix_get_ptr, | |
167 | nbio_mmap_unix_cancel, | |
168 | nbio_mmap_unix_free, | |
169 | "nbio_mmap_unix", | |
170 | }; | |
171 | #else | |
172 | nbio_intf_t nbio_mmap_unix = { | |
173 | NULL, | |
174 | NULL, | |
175 | NULL, | |
176 | NULL, | |
177 | NULL, | |
178 | NULL, | |
179 | NULL, | |
180 | NULL, | |
181 | "nbio_mmap_unix", | |
182 | }; | |
183 | ||
184 | #endif |