summaryrefslogtreecommitdiff
path: root/payloads/libpayload/libc/lar.c
blob: 71f240d80bc13f318cc27f4fb19bc244d436abe3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
/*
 * This file is part of the libpayload project.
 *
 * Copyright (C) 2008 Advanced Micro Devices, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <endian.h>
#include <libpayload.h>

#define ROM_RESET_VECTOR 0xFFFFFFF0

static void * next_header(void * cur)
{
	struct lar_header *header = (struct lar_header *) cur;
	int offset = ((ntohl(header->offset) + ntohl(header->len)) + 15) &
		0xFFFFFFF0;

	return (void *) (cur + offset);
}

static struct lar_header *lar_get_header(struct LAR *lar, int index)
{
	int i;

	if (index < lar->count)
		return (struct lar_header *) lar->headers[index];

	if (lar->eof && index >= lar->eof)
		return NULL;

	for(i = lar->count; i <= index; i++) {
		void *next = (i == 0) ?
			lar->start : next_header(lar->headers[i - 1]);

		if (strncmp((const char *) next, LAR_MAGIC, 8)) {
			lar->eof = lar->count;
			return NULL;
		}

		if (lar->count == lar->alloc) {
			void *tmp = realloc(lar->headers,
					    (lar->alloc + 16) * sizeof(void *));

			if (tmp == NULL)
				return NULL;

			lar->headers = tmp;
			lar->alloc += 16;
		}

		lar->headers[lar->count++] = next;
	}

	return (struct lar_header *) lar->headers[index];
}


/**
 * Open a LAR stream
 *
 * @param addr The address in memory where the LAR is located.
 * Use NULL to specify the boot LAR
 * @return a pointer to the LAR stream
 */

struct LAR *openlar(void *addr)
{
	struct LAR *lar;

	/* If the address is null, then figure out the start of the
	   boot LAR */

	if (addr == NULL) {
		u32 size = *((u32 *) (ROM_RESET_VECTOR + 4));
		addr = (void *) ((ROM_RESET_VECTOR  + 16) - size);
	}

	/* Check the magic to make sure this is a LAR */
	if (strncmp((const char *) addr, LAR_MAGIC, strlen(LAR_MAGIC)))
		return NULL;

	lar = calloc(sizeof(struct LAR), 1);

	if (!lar)
		return NULL;

	lar->start = addr;

	/* Preallocate 16 slots in the cache - this saves wear and
	 * tear on the heap */

	lar->headers = malloc(16 * sizeof(void *));

	if (!lar->headers)
		return NULL;

	lar->alloc = 16;
	lar->count = lar->eof = 0;
	lar->cindex = 0;

	return lar;
}

/**
 * Close a LAR stream
 *
 * @param lar A pointer to the LAR stream
 * @return Return 0 on success, -1 on error
 */

int closelar(struct LAR *lar)
{
	if (!lar)
		return 0;

	if (lar->headers)
		free(lar->headers);

	free(lar);

	return 0;
}

/**
 * Read an entry from the LAR
 *
 * @param lar A pointer to the LAR stream
 * @return A pointer to a larent structure
           representing the next file in the LAR
 */

struct larent *readlar(struct LAR *lar)
{
	static struct larent _larent;
	struct lar_header *header;
	int nlen;

	if (!lar)
		return NULL;

	header = lar_get_header(lar, lar->cindex);

	if (header == NULL)
		return NULL;

	nlen = ntohl(header->offset) - sizeof(*header);

	if (nlen > LAR_MAX_PATHLEN - 1)
		nlen = LAR_MAX_PATHLEN - 1;

	memcpy((void *) _larent.name, ((char *) header + sizeof(*header)),
		nlen);

	_larent.name[nlen] = 0;

	lar->cindex++;

	return (struct larent *) &_larent;
}

void rewindlar(struct LAR *lar)
{
	if (lar != NULL)
		lar->cindex = 0;
}

static struct lar_header *get_header_by_name(struct LAR *lar, const char *name)
{
	struct lar_header *header;
	int i;

	for(i = 0; ; i++) {
		header = lar_get_header(lar, i);

		if (header == NULL)
			return NULL;

		if (!strcmp(name, ((char *) header + sizeof(*header))))
			return header;
	}
}

int larstat(struct LAR *lar, const char *path, struct larstat *buf)
{
	struct lar_header *header = get_header_by_name(lar, path);

	if (header == NULL || buf == NULL)
		return -1;

	buf->len = ntohl(header->len);
	buf->reallen = ntohl(header->reallen);
	buf->checksum = ntohl(header->checksum);
	buf->compchecksum = ntohl(header->compchecksum);
	buf->compression = ntohl(header->compression);
	buf->entry = ntohll(header->entry);
	buf->loadaddress = ntohll(header->loadaddress);
	buf->offset = ((u32) header - (u32) lar->start) + ntohl(header->offset);

	return 0;
}

void * larfptr(struct LAR *lar, const char *filename)
{
	struct lar_header *header = get_header_by_name(lar, filename);

	if (header == NULL)
		return NULL;

	return (void *) ((u8 *) header + ntohl(header->offset));
}

/**
 * Verify the checksum on a particular LAR entry
 *
 * @param lar A pointer to the LAR stream
 * @param filename The lar entry to verify
 * @return Return 1 if the entry is valid, 0 if it is not, or -1
 * on error
 */

int lfverify(struct LAR *lar, const char *filename)
{
	struct lar_header *header = get_header_by_name(lar, filename);

	u8 *ptr = (u8 *) header;
	int len = ntohl(header->len) + ntohl(header->offset);
	int offset;
	u32 csum = 0;

	if (header == NULL)
		return -1;

	/* The checksum needs to be calulated on entire data section,
	 * including any padding for the 16 byte alignment (which should
	 * be zeros
	 */

	len = (len + 15) & 0xFFFFFFF0;

	for(offset = 0; offset < len; offset += 4) {
		csum += *((u32 *) (ptr + offset));
	}

	return (csum == 0xFFFFFFFF) ? 1 : 0;
}

struct LFILE * lfopen(struct LAR *lar, const char *filename)
{
	struct LFILE *file;
	struct lar_header *header = get_header_by_name(lar, filename);

	if (header == NULL)
		return NULL;

	/* FIXME: What other validations do we want to do on the file here? */

	file = malloc(sizeof(struct LFILE));

	if (file == NULL)
		return NULL;

	file->lar = lar;
	file->header = header;
	file->size = ntohl(header->len);
	file->start = ((u8 *) header + ntohl(header->offset));
	file->offset = 0;

	return file;
}

void *lfmap(struct LFILE *file, int offset)
{
	if (file == NULL)
		return (void *) -1;

	if (offset > file->size)
		return (void *) -1;

	return (void *) (file->start + offset);
};

int lfread(void *ptr, size_t size, size_t nmemb, struct LFILE *stream)
{
	size_t tsize, actual;
	size_t remain = stream->size - stream->offset;

	if (!stream || !remain)
		return 0;

	tsize = (size * nmemb);
	actual = (tsize > remain) ? remain : tsize;

	memcpy(ptr, (void *) (stream->start + stream->offset), actual);
	stream->offset += actual;

	return actual;
}

int lfseek(struct LFILE *file, long offset, int whence)
{
	int o = file->offset;

	switch(whence) {
	case SEEK_SET:
		o = offset;
		break;
	case SEEK_CUR:
		o += offset;
		break;

	case SEEK_END:
		return -1;
	}

	if (o < 0 || o > file->size)
		return -1;

	file->offset = o;
	return file->offset;
}

int lfclose(struct LFILE *file)
{
	if (file)
		free(file);
	return 0;
}