1 /*-
2 * Copyright (c) 2016 Landon Fuller <landonf@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer,
10 * without modification.
11 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13 * redistribution must be conditioned upon including a substantially
14 * similar Disclaimer requirement for further binary redistribution.
15 *
16 * NO WARRANTY
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
22 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
25 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27 * THE POSSIBILITY OF SUCH DAMAGES.
28 */
29
30 #include <sys/cdefs.h>
31 #ifdef _KERNEL
32 #include <sys/param.h>
33 #include <sys/malloc.h>
34 #include <sys/systm.h>
35 #else /* !_KERNEL */
36 #include <errno.h>
37 #include <stdint.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #endif /* _KERNEL */
41
42 #include "bhnd_nvram_private.h"
43
44 #include "bhnd_nvram_io.h"
45 #include "bhnd_nvram_iovar.h"
46
47 /**
48 * Buffer-backed NVRAM I/O context.
49 *
50 * iobuf instances are gauranteed to provide persistent references to its
51 * backing contigious buffer via bhnd_nvram_io_read_ptr() and
52 * bhnd_nvram_io_write_ptr().
53 */
54 struct bhnd_nvram_iobuf {
55 struct bhnd_nvram_io io; /**< common I/O instance state */
56 void *buf; /**< backing buffer. if inline-allocated, will
57 be a reference to data[]. */
58 size_t size; /**< size of @p buf */
59 size_t capacity; /**< capacity of @p buf */
60 uint8_t data[]; /**< inline buffer allocation */
61 };
62
BHND_NVRAM_IOPS_DEFN(iobuf)63 BHND_NVRAM_IOPS_DEFN(iobuf)
64
65 /**
66 * Allocate and return a new I/O context with an uninitialized
67 * buffer of @p size and @p capacity.
68 *
69 * The caller is responsible for deallocating the returned I/O context via
70 * bhnd_nvram_io_free().
71 *
72 * If @p capacity is less than @p size, a capacity of @p size will be used.
73 *
74 * @param size The initial size of the I/O context.
75 * @param capacity The total capacity of the I/O context buffer;
76 * the returned I/O context may be resized up to
77 * @p capacity via bhnd_nvram_io_setsize().
78 *
79 * @retval bhnd_nvram_iobuf success.
80 * @retval NULL allocation failed.
81 * @retval NULL the requested @p capacity is less than
82 * @p size.
83 */
84 struct bhnd_nvram_io *
85 bhnd_nvram_iobuf_empty(size_t size, size_t capacity)
86 {
87 struct bhnd_nvram_iobuf *iobuf;
88 size_t iosz;
89 bool inline_alloc;
90
91 /* Sanity check the capacity */
92 if (size > capacity)
93 return (NULL);
94
95 /* Would sizeof(iobuf)+capacity overflow? */
96 if (SIZE_MAX - sizeof(*iobuf) < capacity) {
97 inline_alloc = false;
98 iosz = sizeof(*iobuf);
99 } else {
100 inline_alloc = true;
101 iosz = sizeof(*iobuf) + capacity;
102 }
103
104 /* Allocate I/O context */
105 iobuf = bhnd_nv_malloc(iosz);
106 if (iobuf == NULL)
107 return (NULL);
108
109 iobuf->io.iops = &bhnd_nvram_iobuf_ops;
110 iobuf->buf = NULL;
111 iobuf->size = size;
112 iobuf->capacity = capacity;
113
114 /* Either allocate our backing buffer, or initialize the
115 * backing buffer with a reference to our inline allocation. */
116 if (inline_alloc)
117 iobuf->buf = &iobuf->data;
118 else
119 iobuf->buf = bhnd_nv_malloc(iobuf->capacity);
120
121 if (iobuf->buf == NULL) {
122 bhnd_nv_free(iobuf);
123 return (NULL);
124 }
125
126 return (&iobuf->io);
127 }
128
129 /**
130 * Allocate and return a new I/O context, copying @p size from @p buffer.
131 *
132 * The caller is responsible for deallocating the returned I/O context via
133 * bhnd_nvram_io_free().
134 *
135 * @param buffer The buffer data be copied by the returned I/O context.
136 * @param size The size of @p buffer, in bytes.
137 *
138 * @retval bhnd_nvram_io success.
139 * @retval NULL allocation failed.
140 */
141 struct bhnd_nvram_io *
bhnd_nvram_iobuf_new(const void * buffer,size_t size)142 bhnd_nvram_iobuf_new(const void *buffer, size_t size)
143 {
144 struct bhnd_nvram_io *io;
145 struct bhnd_nvram_iobuf *iobuf;
146
147 /* Allocate the iobuf */
148 if ((io = bhnd_nvram_iobuf_empty(size, size)) == NULL)
149 return (NULL);
150
151 /* Copy the input to our new iobuf instance */
152 iobuf = (struct bhnd_nvram_iobuf *)io;
153 memcpy(iobuf->buf, buffer, iobuf->size);
154
155 return (io);
156 }
157
158 /**
159 * Allocate and return a new I/O context providing an in-memory copy
160 * of the data mapped by @p src.
161 *
162 * The caller is responsible for deallocating the returned I/O context via
163 * bhnd_nvram_io_free().
164 *
165 * @param src The I/O context to be copied.
166 *
167 * @retval bhnd_nvram_io success.
168 * @retval NULL allocation failed.
169 * @retval NULL copying @p src failed.
170 */
171 struct bhnd_nvram_io *
bhnd_nvram_iobuf_copy(struct bhnd_nvram_io * src)172 bhnd_nvram_iobuf_copy(struct bhnd_nvram_io *src)
173 {
174 return (bhnd_nvram_iobuf_copy_range(src, 0x0,
175 bhnd_nvram_io_getsize(src)));
176 }
177
178 /**
179 * Allocate and return a new I/O context providing an in-memory copy
180 * of @p size bytes mapped at @p offset by @p src.
181 *
182 * The caller is responsible for deallocating the returned I/O context via
183 * bhnd_nvram_io_free().
184 *
185 * @param src The I/O context to be copied.
186 * @param offset The offset of the bytes to be copied from @p src.
187 * @param size The number of bytes to copy at @p offset from @p src.
188 *
189 * @retval bhnd_nvram_io success.
190 * @retval NULL allocation failed.
191 * @retval NULL copying @p src failed.
192 */
193 struct bhnd_nvram_io *
bhnd_nvram_iobuf_copy_range(struct bhnd_nvram_io * src,size_t offset,size_t size)194 bhnd_nvram_iobuf_copy_range(struct bhnd_nvram_io *src, size_t offset,
195 size_t size)
196 {
197 struct bhnd_nvram_io *io;
198 struct bhnd_nvram_iobuf *iobuf;
199 int error;
200
201 /* Check if offset+size would overflow */
202 if (SIZE_MAX - size < offset)
203 return (NULL);
204
205 /* Allocate the iobuf instance */
206 if ((io = bhnd_nvram_iobuf_empty(size, size)) == NULL)
207 return (NULL);
208
209 /* Copy the input I/O context */
210 iobuf = (struct bhnd_nvram_iobuf *)io;
211 if ((error = bhnd_nvram_io_read(src, offset, iobuf->buf, size))) {
212 bhnd_nvram_io_free(&iobuf->io);
213 return (NULL);
214 }
215
216 return (io);
217 }
218
219 static void
bhnd_nvram_iobuf_free(struct bhnd_nvram_io * io)220 bhnd_nvram_iobuf_free(struct bhnd_nvram_io *io)
221 {
222 struct bhnd_nvram_iobuf *iobuf = (struct bhnd_nvram_iobuf *)io;
223
224 /* Free the backing buffer if it wasn't allocated inline */
225 if (iobuf->buf != &iobuf->data)
226 bhnd_nv_free(iobuf->buf);
227
228 bhnd_nv_free(iobuf);
229 }
230
231 static size_t
bhnd_nvram_iobuf_getsize(struct bhnd_nvram_io * io)232 bhnd_nvram_iobuf_getsize(struct bhnd_nvram_io *io)
233 {
234 struct bhnd_nvram_iobuf *iobuf = (struct bhnd_nvram_iobuf *)io;
235 return (iobuf->size);
236 }
237
238 static int
bhnd_nvram_iobuf_setsize(struct bhnd_nvram_io * io,size_t size)239 bhnd_nvram_iobuf_setsize(struct bhnd_nvram_io *io, size_t size)
240 {
241 struct bhnd_nvram_iobuf *iobuf = (struct bhnd_nvram_iobuf *)io;
242
243 /* Can't exceed the actual capacity */
244 if (size > iobuf->capacity)
245 return (ENXIO);
246
247 iobuf->size = size;
248 return (0);
249 }
250
251 /* Common iobuf_(read|write)_ptr implementation */
252 static int
bhnd_nvram_iobuf_ptr(struct bhnd_nvram_iobuf * iobuf,size_t offset,void ** ptr,size_t nbytes,size_t * navail)253 bhnd_nvram_iobuf_ptr(struct bhnd_nvram_iobuf *iobuf, size_t offset, void **ptr,
254 size_t nbytes, size_t *navail)
255 {
256 size_t avail;
257
258 /* Verify offset+nbytes fall within the buffer range */
259 if (offset > iobuf->size)
260 return (ENXIO);
261
262 avail = iobuf->size - offset;
263 if (avail < nbytes)
264 return (ENXIO);
265
266 /* Valid I/O range, provide a pointer to the buffer and the
267 * total count of available bytes */
268 *ptr = ((uint8_t *)iobuf->buf) + offset;
269 if (navail != NULL)
270 *navail = avail;
271
272 return (0);
273 }
274
275 static int
bhnd_nvram_iobuf_read_ptr(struct bhnd_nvram_io * io,size_t offset,const void ** ptr,size_t nbytes,size_t * navail)276 bhnd_nvram_iobuf_read_ptr(struct bhnd_nvram_io *io, size_t offset,
277 const void **ptr, size_t nbytes, size_t *navail)
278 {
279 struct bhnd_nvram_iobuf *iobuf;
280 void *ioptr;
281 int error;
282
283 iobuf = (struct bhnd_nvram_iobuf *) io;
284
285 /* Return a pointer into our backing buffer */
286 error = bhnd_nvram_iobuf_ptr(iobuf, offset, &ioptr, nbytes, navail);
287 if (error)
288 return (error);
289
290 *ptr = ioptr;
291
292 return (0);
293 }
294
295 static int
bhnd_nvram_iobuf_write_ptr(struct bhnd_nvram_io * io,size_t offset,void ** ptr,size_t nbytes,size_t * navail)296 bhnd_nvram_iobuf_write_ptr(struct bhnd_nvram_io *io, size_t offset,
297 void **ptr, size_t nbytes, size_t *navail)
298 {
299 struct bhnd_nvram_iobuf *iobuf;
300
301 iobuf = (struct bhnd_nvram_iobuf *) io;
302
303 /* Return a pointer into our backing buffer */
304 return (bhnd_nvram_iobuf_ptr(iobuf, offset, ptr, nbytes, navail));
305 }
306
307 static int
bhnd_nvram_iobuf_read(struct bhnd_nvram_io * io,size_t offset,void * buffer,size_t nbytes)308 bhnd_nvram_iobuf_read(struct bhnd_nvram_io *io, size_t offset, void *buffer,
309 size_t nbytes)
310 {
311 const void *ptr;
312 int error;
313
314 /* Try to fetch a direct pointer for at least nbytes */
315 if ((error = bhnd_nvram_io_read_ptr(io, offset, &ptr, nbytes, NULL)))
316 return (error);
317
318 /* Copy out the requested data */
319 memcpy(buffer, ptr, nbytes);
320 return (0);
321 }
322
323 static int
bhnd_nvram_iobuf_write(struct bhnd_nvram_io * io,size_t offset,void * buffer,size_t nbytes)324 bhnd_nvram_iobuf_write(struct bhnd_nvram_io *io, size_t offset,
325 void *buffer, size_t nbytes)
326 {
327 void *ptr;
328 int error;
329
330 /* Try to fetch a direct pointer for at least nbytes */
331 if ((error = bhnd_nvram_io_write_ptr(io, offset, &ptr, nbytes, NULL)))
332 return (error);
333
334 /* Copy in the provided data */
335 memcpy(ptr, buffer, nbytes);
336 return (0);
337 }
338