1/*
2 * libwebsockets - small server side websockets and web server implementation
3 *
4 * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to
8 * deal in the Software without restriction, including without limitation the
9 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10 * sell copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22 * IN THE SOFTWARE.
23 */
24
25/*! \defgroup fops file operation wrapping
26 *
27 * ##File operation wrapping
28 *
29 * Use these helper functions if you want to access a file from the perspective
30 * of a specific wsi, which is usually the case. If you just want contextless
31 * file access, use the fops callbacks directly with NULL wsi instead of these
32 * helpers.
33 *
34 * If so, then it calls the platform handler or user overrides where present
35 * (as defined in info->fops)
36 *
37 * The advantage from all this is user code can be portable for file operations
38 * without having to deal with differences between platforms.
39 */
40//@{
41
42/** struct lws_plat_file_ops - Platform-specific file operations
43 *
44 * These provide platform-agnostic ways to deal with filesystem access in the
45 * library and in the user code.
46 */
47
48#if defined(LWS_PLAT_FREERTOS)
49/* sdk preprocessor defs? compiler issue? gets confused with member names */
50#define LWS_FOP_OPEN _open
51#define LWS_FOP_CLOSE _close
52#define LWS_FOP_SEEK_CUR _seek_cur
53#define LWS_FOP_READ _read
54#define LWS_FOP_WRITE _write
55#else
56#define LWS_FOP_OPEN open
57#define LWS_FOP_CLOSE close
58#define LWS_FOP_SEEK_CUR seek_cur
59#define LWS_FOP_READ read
60#define LWS_FOP_WRITE write
61#endif
62
63#define LWS_FOP_FLAGS_MASK ((1 << 23) - 1)
64#define LWS_FOP_FLAG_COMPR_ACCEPTABLE_GZIP (1 << 24)
65#define LWS_FOP_FLAG_COMPR_IS_GZIP (1 << 25)
66#define LWS_FOP_FLAG_MOD_TIME_VALID (1 << 26)
67#define LWS_FOP_FLAG_VIRTUAL (1 << 27)
68
69struct lws_plat_file_ops;
70
71struct lws_fop_fd {
72 lws_filefd_type fd;
73 /**< real file descriptor related to the file... */
74 const struct lws_plat_file_ops *fops;
75 /**< fops that apply to this fop_fd */
76 void *filesystem_priv;
77 /**< ignored by lws; owned by the fops handlers */
78 lws_filepos_t pos;
79 /**< generic "position in file" */
80 lws_filepos_t len;
81 /**< generic "length of file" */
82 lws_fop_flags_t flags;
83 /**< copy of the returned flags */
84 uint32_t mod_time;
85 /**< optional "modification time of file", only valid if .open()
86 * set the LWS_FOP_FLAG_MOD_TIME_VALID flag */
87};
88typedef struct lws_fop_fd *lws_fop_fd_t;
89
90struct lws_fops_index {
91 const char *sig; /* NULL or vfs signature, eg, ".zip/" */
92 uint8_t len; /* length of above string */
93};
94
95struct lws_plat_file_ops {
96 lws_fop_fd_t (*LWS_FOP_OPEN)(const struct lws_plat_file_ops *fops,
97 const char *filename, const char *vpath,
98 lws_fop_flags_t *flags);
99 /**< Open file (always binary access if plat supports it)
100 * vpath may be NULL, or if the fops understands it, the point at which
101 * the filename's virtual part starts.
102 * *flags & LWS_FOP_FLAGS_MASK should be set to O_RDONLY or O_RDWR.
103 * If the file may be gzip-compressed,
104 * LWS_FOP_FLAG_COMPR_ACCEPTABLE_GZIP is set. If it actually is
105 * gzip-compressed, then the open handler should OR
106 * LWS_FOP_FLAG_COMPR_IS_GZIP on to *flags before returning.
107 */
108 int (*LWS_FOP_CLOSE)(lws_fop_fd_t *fop_fd);
109 /**< close file AND set the pointer to NULL */
110 lws_fileofs_t (*LWS_FOP_SEEK_CUR)(lws_fop_fd_t fop_fd,
111 lws_fileofs_t offset_from_cur_pos);
112 /**< seek from current position */
113 int (*LWS_FOP_READ)(lws_fop_fd_t fop_fd, lws_filepos_t *amount,
114 uint8_t *buf, lws_filepos_t len);
115 /**< Read from file, on exit *amount is set to amount actually read */
116 int (*LWS_FOP_WRITE)(lws_fop_fd_t fop_fd, lws_filepos_t *amount,
117 uint8_t *buf, lws_filepos_t len);
118 /**< Write to file, on exit *amount is set to amount actually written */
119
120 struct lws_fops_index fi[3];
121 /**< vfs path signatures implying use of this fops */
122
123 const struct lws_plat_file_ops *next;
124 /**< NULL or next fops in list */
125
126 /* Add new things just above here ---^
127 * This is part of the ABI, don't needlessly break compatibility */
128};
129
130/**
131 * lws_get_fops() - get current file ops
132 *
133 * \param context: context
134 */
135LWS_VISIBLE LWS_EXTERN struct lws_plat_file_ops * LWS_WARN_UNUSED_RESULT
136lws_get_fops(struct lws_context *context);
137LWS_VISIBLE LWS_EXTERN void
138lws_set_fops(struct lws_context *context, const struct lws_plat_file_ops *fops);
139/**
140 * lws_vfs_tell() - get current file position
141 *
142 * \param fop_fd: fop_fd we are asking about
143 */
144LWS_VISIBLE LWS_EXTERN lws_filepos_t LWS_WARN_UNUSED_RESULT
145lws_vfs_tell(lws_fop_fd_t fop_fd);
146/**
147 * lws_vfs_get_length() - get current file total length in bytes
148 *
149 * \param fop_fd: fop_fd we are asking about
150 */
151LWS_VISIBLE LWS_EXTERN lws_filepos_t LWS_WARN_UNUSED_RESULT
152lws_vfs_get_length(lws_fop_fd_t fop_fd);
153/**
154 * lws_vfs_get_mod_time() - get time file last modified
155 *
156 * \param fop_fd: fop_fd we are asking about
157 */
158LWS_VISIBLE LWS_EXTERN uint32_t LWS_WARN_UNUSED_RESULT
159lws_vfs_get_mod_time(lws_fop_fd_t fop_fd);
160/**
161 * lws_vfs_file_seek_set() - seek relative to start of file
162 *
163 * \param fop_fd: fop_fd we are seeking in
164 * \param offset: offset from start of file
165 */
166LWS_VISIBLE LWS_EXTERN lws_fileofs_t
167lws_vfs_file_seek_set(lws_fop_fd_t fop_fd, lws_fileofs_t offset);
168/**
169 * lws_vfs_file_seek_end() - seek relative to end of file
170 *
171 * \param fop_fd: fop_fd we are seeking in
172 * \param offset: offset from start of file
173 */
174LWS_VISIBLE LWS_EXTERN lws_fileofs_t
175lws_vfs_file_seek_end(lws_fop_fd_t fop_fd, lws_fileofs_t offset);
176
177extern struct lws_plat_file_ops fops_zip;
178
179/**
180 * lws_plat_file_open() - open vfs filepath
181 *
182 * \param fops: file ops struct that applies to this descriptor
183 * \param vfs_path: filename to open
184 * \param flags: pointer to open flags
185 *
186 * The vfs_path is scanned for known fops signatures, and the open directed
187 * to any matching fops open.
188 *
189 * User code should use this api to perform vfs opens.
190 *
191 * returns semi-opaque handle
192 */
193LWS_VISIBLE LWS_EXTERN lws_fop_fd_t LWS_WARN_UNUSED_RESULT
194lws_vfs_file_open(const struct lws_plat_file_ops *fops, const char *vfs_path,
195 lws_fop_flags_t *flags);
196
197/**
198 * lws_plat_file_close() - close file
199 *
200 * \param fop_fd: file handle to close
201 */
202static LWS_INLINE int
203lws_vfs_file_close(lws_fop_fd_t *fop_fd)
204{
205 if (*fop_fd && (*fop_fd)->fops)
206 return (*fop_fd)->fops->LWS_FOP_CLOSE(fop_fd);
207
208 return 0;
209}
210
211/**
212 * lws_plat_file_seek_cur() - close file
213 *
214 *
215 * \param fop_fd: file handle
216 * \param offset: position to seek to
217 */
218static LWS_INLINE lws_fileofs_t
219lws_vfs_file_seek_cur(lws_fop_fd_t fop_fd, lws_fileofs_t offset)
220{
221 return fop_fd->fops->LWS_FOP_SEEK_CUR(fop_fd, offset);
222}
223/**
224 * lws_plat_file_read() - read from file
225 *
226 * \param fop_fd: file handle
227 * \param amount: how much to read (rewritten by call)
228 * \param buf: buffer to write to
229 * \param len: max length
230 */
231static LWS_INLINE int LWS_WARN_UNUSED_RESULT
232lws_vfs_file_read(lws_fop_fd_t fop_fd, lws_filepos_t *amount,
233 uint8_t *buf, lws_filepos_t len)
234{
235 return fop_fd->fops->LWS_FOP_READ(fop_fd, amount, buf, len);
236}
237/**
238 * lws_plat_file_write() - write from file
239 *
240 * \param fop_fd: file handle
241 * \param amount: how much to write (rewritten by call)
242 * \param buf: buffer to read from
243 * \param len: max length
244 */
245static LWS_INLINE int LWS_WARN_UNUSED_RESULT
246lws_vfs_file_write(lws_fop_fd_t fop_fd, lws_filepos_t *amount,
247 uint8_t *buf, lws_filepos_t len)
248{
249 return fop_fd->fops->LWS_FOP_WRITE(fop_fd, amount, buf, len);
250}
251
252/* these are the platform file operations implementations... they can
253 * be called directly and used in fops arrays
254 */
255
256LWS_VISIBLE LWS_EXTERN lws_fop_fd_t
257_lws_plat_file_open(const struct lws_plat_file_ops *fops, const char *filename,
258 const char *vpath, lws_fop_flags_t *flags);
259LWS_VISIBLE LWS_EXTERN int
260_lws_plat_file_close(lws_fop_fd_t *fop_fd);
261LWS_VISIBLE LWS_EXTERN lws_fileofs_t
262_lws_plat_file_seek_cur(lws_fop_fd_t fop_fd, lws_fileofs_t offset);
263LWS_VISIBLE LWS_EXTERN int
264_lws_plat_file_read(lws_fop_fd_t fop_fd, lws_filepos_t *amount,
265 uint8_t *buf, lws_filepos_t len);
266LWS_VISIBLE LWS_EXTERN int
267_lws_plat_file_write(lws_fop_fd_t fop_fd, lws_filepos_t *amount,
268 uint8_t *buf, lws_filepos_t len);
269
270LWS_VISIBLE LWS_EXTERN int
271lws_alloc_vfs_file(struct lws_context *context, const char *filename,
272 uint8_t **buf, lws_filepos_t *amount);
273//@}
274