Free Electrons

Embedded Linux Experts

  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
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
#include <netinet/in.h>
#ifdef __sun__
#include <inttypes.h>
#else
#include <stdint.h>
#endif
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <limits.h>
#include "modpost.h"

/*
 * Stolen form Cryptographic API.
 *
 * MD4 Message Digest Algorithm (RFC1320).
 *
 * Implementation derived from Andrew Tridgell and Steve French's
 * CIFS MD4 implementation, and the cryptoapi implementation
 * originally based on the public domain implementation written
 * by Colin Plumb in 1993.
 *
 * Copyright (c) Andrew Tridgell 1997-1998.
 * Modified by Steve French (sfrench@us.ibm.com) 2002
 * Copyright (c) Cryptoapi developers.
 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 */
#define MD4_DIGEST_SIZE		16
#define MD4_HMAC_BLOCK_SIZE	64
#define MD4_BLOCK_WORDS		16
#define MD4_HASH_WORDS		4

struct md4_ctx {
	uint32_t hash[MD4_HASH_WORDS];
	uint32_t block[MD4_BLOCK_WORDS];
	uint64_t byte_count;
};

static inline uint32_t lshift(uint32_t x, unsigned int s)
{
	x &= 0xFFFFFFFF;
	return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
}

static inline uint32_t F(uint32_t x, uint32_t y, uint32_t z)
{
	return (x & y) | ((~x) & z);
}

static inline uint32_t G(uint32_t x, uint32_t y, uint32_t z)
{
	return (x & y) | (x & z) | (y & z);
}

static inline uint32_t H(uint32_t x, uint32_t y, uint32_t z)
{
	return x ^ y ^ z;
}

#define ROUND1(a,b,c,d,k,s) (a = lshift(a + F(b,c,d) + k, s))
#define ROUND2(a,b,c,d,k,s) (a = lshift(a + G(b,c,d) + k + (uint32_t)0x5A827999,s))
#define ROUND3(a,b,c,d,k,s) (a = lshift(a + H(b,c,d) + k + (uint32_t)0x6ED9EBA1,s))

/* XXX: this stuff can be optimized */
static inline void le32_to_cpu_array(uint32_t *buf, unsigned int words)
{
	while (words--) {
		*buf = ntohl(*buf);
		buf++;
	}
}

static inline void cpu_to_le32_array(uint32_t *buf, unsigned int words)
{
	while (words--) {
		*buf = htonl(*buf);
		buf++;
	}
}

static void md4_transform(uint32_t *hash, uint32_t const *in)
{
	uint32_t a, b, c, d;

	a = hash[0];
	b = hash[1];
	c = hash[2];
	d = hash[3];

	ROUND1(a, b, c, d, in[0], 3);
	ROUND1(d, a, b, c, in[1], 7);
	ROUND1(c, d, a, b, in[2], 11);
	ROUND1(b, c, d, a, in[3], 19);
	ROUND1(a, b, c, d, in[4], 3);
	ROUND1(d, a, b, c, in[5], 7);
	ROUND1(c, d, a, b, in[6], 11);
	ROUND1(b, c, d, a, in[7], 19);
	ROUND1(a, b, c, d, in[8], 3);
	ROUND1(d, a, b, c, in[9], 7);
	ROUND1(c, d, a, b, in[10], 11);
	ROUND1(b, c, d, a, in[11], 19);
	ROUND1(a, b, c, d, in[12], 3);
	ROUND1(d, a, b, c, in[13], 7);
	ROUND1(c, d, a, b, in[14], 11);
	ROUND1(b, c, d, a, in[15], 19);

	ROUND2(a, b, c, d,in[ 0], 3);
	ROUND2(d, a, b, c, in[4], 5);
	ROUND2(c, d, a, b, in[8], 9);
	ROUND2(b, c, d, a, in[12], 13);
	ROUND2(a, b, c, d, in[1], 3);
	ROUND2(d, a, b, c, in[5], 5);
	ROUND2(c, d, a, b, in[9], 9);
	ROUND2(b, c, d, a, in[13], 13);
	ROUND2(a, b, c, d, in[2], 3);
	ROUND2(d, a, b, c, in[6], 5);
	ROUND2(c, d, a, b, in[10], 9);
	ROUND2(b, c, d, a, in[14], 13);
	ROUND2(a, b, c, d, in[3], 3);
	ROUND2(d, a, b, c, in[7], 5);
	ROUND2(c, d, a, b, in[11], 9);
	ROUND2(b, c, d, a, in[15], 13);

	ROUND3(a, b, c, d,in[ 0], 3);
	ROUND3(d, a, b, c, in[8], 9);
	ROUND3(c, d, a, b, in[4], 11);
	ROUND3(b, c, d, a, in[12], 15);
	ROUND3(a, b, c, d, in[2], 3);
	ROUND3(d, a, b, c, in[10], 9);
	ROUND3(c, d, a, b, in[6], 11);
	ROUND3(b, c, d, a, in[14], 15);
	ROUND3(a, b, c, d, in[1], 3);
	ROUND3(d, a, b, c, in[9], 9);
	ROUND3(c, d, a, b, in[5], 11);
	ROUND3(b, c, d, a, in[13], 15);
	ROUND3(a, b, c, d, in[3], 3);
	ROUND3(d, a, b, c, in[11], 9);
	ROUND3(c, d, a, b, in[7], 11);
	ROUND3(b, c, d, a, in[15], 15);

	hash[0] += a;
	hash[1] += b;
	hash[2] += c;
	hash[3] += d;
}

static inline void md4_transform_helper(struct md4_ctx *ctx)
{
	le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(uint32_t));
	md4_transform(ctx->hash, ctx->block);
}

static void md4_init(struct md4_ctx *mctx)
{
	mctx->hash[0] = 0x67452301;
	mctx->hash[1] = 0xefcdab89;
	mctx->hash[2] = 0x98badcfe;
	mctx->hash[3] = 0x10325476;
	mctx->byte_count = 0;
}

static void md4_update(struct md4_ctx *mctx,
		       const unsigned char *data, unsigned int len)
{
	const uint32_t avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);

	mctx->byte_count += len;

	if (avail > len) {
		memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
		       data, len);
		return;
	}

	memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
	       data, avail);

	md4_transform_helper(mctx);
	data += avail;
	len -= avail;

	while (len >= sizeof(mctx->block)) {
		memcpy(mctx->block, data, sizeof(mctx->block));
		md4_transform_helper(mctx);
		data += sizeof(mctx->block);
		len -= sizeof(mctx->block);
	}

	memcpy(mctx->block, data, len);
}

static void md4_final_ascii(struct md4_ctx *mctx, char *out, unsigned int len)
{
	const unsigned int offset = mctx->byte_count & 0x3f;
	char *p = (char *)mctx->block + offset;
	int padding = 56 - (offset + 1);

	*p++ = 0x80;
	if (padding < 0) {
		memset(p, 0x00, padding + sizeof (uint64_t));
		md4_transform_helper(mctx);
		p = (char *)mctx->block;
		padding = 56;
	}

	memset(p, 0, padding);
	mctx->block[14] = mctx->byte_count << 3;
	mctx->block[15] = mctx->byte_count >> 29;
	le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
			  sizeof(uint64_t)) / sizeof(uint32_t));
	md4_transform(mctx->hash, mctx->block);
	cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(uint32_t));

	snprintf(out, len, "%08X%08X%08X%08X",
		 mctx->hash[0], mctx->hash[1], mctx->hash[2], mctx->hash[3]);
}

static inline void add_char(unsigned char c, struct md4_ctx *md)
{
	md4_update(md, &c, 1);
}

static int parse_string(const char *file, unsigned long len,
			struct md4_ctx *md)
{
	unsigned long i;

	add_char(file[0], md);
	for (i = 1; i < len; i++) {
		add_char(file[i], md);
		if (file[i] == '"' && file[i-1] != '\\')
			break;
	}
	return i;
}

static int parse_comment(const char *file, unsigned long len)
{
	unsigned long i;

	for (i = 2; i < len; i++) {
		if (file[i-1] == '*' && file[i] == '/')
			break;
	}
	return i;
}

/* FIXME: Handle .s files differently (eg. # starts comments) --RR */
static int parse_file(const char *fname, struct md4_ctx *md)
{
	char *file;
	unsigned long i, len;

	file = grab_file(fname, &len);
	if (!file)
		return 0;

	for (i = 0; i < len; i++) {
		/* Collapse and ignore \ and CR. */
		if (file[i] == '\\' && (i+1 < len) && file[i+1] == '\n') {
			i++;
			continue;
		}

		/* Ignore whitespace */
		if (isspace(file[i]))
			continue;

		/* Handle strings as whole units */
		if (file[i] == '"') {
			i += parse_string(file+i, len - i, md);
			continue;
		}

		/* Comments: ignore */
		if (file[i] == '/' && file[i+1] == '*') {
			i += parse_comment(file+i, len - i);
			continue;
		}

		add_char(file[i], md);
	}
	release_file(file, len);
	return 1;
}
/* Check whether the file is a static library or not */
static int is_static_library(const char *objfile)
{
	int len = strlen(objfile);
	if (objfile[len - 2] == '.' && objfile[len - 1] == 'a')
		return 1;
	else
		return 0;
}

/* We have dir/file.o.  Open dir/.file.o.cmd, look for source_ and deps_ line
 * to figure out source files. */
static int parse_source_files(const char *objfile, struct md4_ctx *md)
{
	char *cmd, *file, *line, *dir;
	const char *base;
	unsigned long flen, pos = 0;
	int dirlen, ret = 0, check_files = 0;

	cmd = NOFAIL(malloc(strlen(objfile) + sizeof("..cmd")));

	base = strrchr(objfile, '/');
	if (base) {
		base++;
		dirlen = base - objfile;
		sprintf(cmd, "%.*s.%s.cmd", dirlen, objfile, base);
	} else {
		dirlen = 0;
		sprintf(cmd, ".%s.cmd", objfile);
	}
	dir = NOFAIL(malloc(dirlen + 1));
	strncpy(dir, objfile, dirlen);
	dir[dirlen] = '\0';

	file = grab_file(cmd, &flen);
	if (!file) {
		warn("could not find %s for %s\n", cmd, objfile);
		goto out;
	}

	/* There will be a line like so:
		deps_drivers/net/dummy.o := \
		  drivers/net/dummy.c \
		    $(wildcard include/config/net/fastroute.h) \
		  include/linux/module.h \

	   Sum all files in the same dir or subdirs.
	*/
	while ((line = get_next_line(&pos, file, flen)) != NULL) {
		char* p = line;

		if (strncmp(line, "source_", sizeof("source_")-1) == 0) {
			p = strrchr(line, ' ');
			if (!p) {
				warn("malformed line: %s\n", line);
				goto out_file;
			}
			p++;
			if (!parse_file(p, md)) {
				warn("could not open %s: %s\n",
				     p, strerror(errno));
				goto out_file;
			}
			continue;
		}
		if (strncmp(line, "deps_", sizeof("deps_")-1) == 0) {
			check_files = 1;
			continue;
		}
		if (!check_files)
			continue;

		/* Continue until line does not end with '\' */
		if ( *(p + strlen(p)-1) != '\\')
			break;
		/* Terminate line at first space, to get rid of final ' \' */
		while (*p) {
			if (isspace(*p)) {
				*p = '\0';
				break;
			}
			p++;
		}

		/* Check if this file is in same dir as objfile */
		if ((strstr(line, dir)+strlen(dir)-1) == strrchr(line, '/')) {
			if (!parse_file(line, md)) {
				warn("could not open %s: %s\n",
				     line, strerror(errno));
				goto out_file;
			}

		}

	}

	/* Everyone parsed OK */
	ret = 1;
out_file:
	release_file(file, flen);
out:
	free(dir);
	free(cmd);
	return ret;
}

/* Calc and record src checksum. */
void get_src_version(const char *modname, char sum[], unsigned sumlen)
{
	void *file;
	unsigned long len;
	struct md4_ctx md;
	char *sources, *end, *fname;
	const char *basename;
	char filelist[PATH_MAX + 1];
	char *modverdir = getenv("MODVERDIR");

	if (!modverdir)
		modverdir = ".";

	/* Source files for module are in .tmp_versions/modname.mod,
	   after the first line. */
	if (strrchr(modname, '/'))
		basename = strrchr(modname, '/') + 1;
	else
		basename = modname;
	snprintf(filelist, sizeof(filelist), "%s/%.*s.mod", modverdir,
		(int) strlen(basename) - 2, basename);

	file = grab_file(filelist, &len);
	if (!file)
		/* not a module or .mod file missing - ignore */
		return;

	sources = strchr(file, '\n');
	if (!sources) {
		warn("malformed versions file for %s\n", modname);
		goto release;
	}

	sources++;
	end = strchr(sources, '\n');
	if (!end) {
		warn("bad ending versions file for %s\n", modname);
		goto release;
	}
	*end = '\0';

	md4_init(&md);
	while ((fname = strsep(&sources, " ")) != NULL) {
		if (!*fname)
			continue;
		if (!(is_static_library(fname)) &&
				!parse_source_files(fname, &md))
			goto release;
	}

	md4_final_ascii(&md, sum, sumlen);
release:
	release_file(file, len);
}

static void write_version(const char *filename, const char *sum,
			  unsigned long offset)
{
	int fd;

	fd = open(filename, O_RDWR);
	if (fd < 0) {
		warn("changing sum in %s failed: %s\n",
			filename, strerror(errno));
		return;
	}

	if (lseek(fd, offset, SEEK_SET) == (off_t)-1) {
		warn("changing sum in %s:%lu failed: %s\n",
			filename, offset, strerror(errno));
		goto out;
	}

	if (write(fd, sum, strlen(sum)+1) != strlen(sum)+1) {
		warn("writing sum in %s failed: %s\n",
			filename, strerror(errno));
		goto out;
	}
out:
	close(fd);
}

static int strip_rcs_crap(char *version)
{
	unsigned int len, full_len;

	if (strncmp(version, "$Revision", strlen("$Revision")) != 0)
		return 0;

	/* Space for version string follows. */
	full_len = strlen(version) + strlen(version + strlen(version) + 1) + 2;

	/* Move string to start with version number: prefix will be
	 * $Revision$ or $Revision: */
	len = strlen("$Revision");
	if (version[len] == ':' || version[len] == '$')
		len++;
	while (isspace(version[len]))
		len++;
	memmove(version, version+len, full_len-len);
	full_len -= len;

	/* Preserve up to next whitespace. */
	len = 0;
	while (version[len] && !isspace(version[len]))
		len++;
	memmove(version + len, version + strlen(version),
		full_len - strlen(version));
	return 1;
}

/* Clean up RCS-style version numbers. */
void maybe_frob_rcs_version(const char *modfilename,
			    char *version,
			    void *modinfo,
			    unsigned long version_offset)
{
	if (strip_rcs_crap(version))
		write_version(modfilename, version, version_offset);
}