1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
23 */
24
25 #include <stdio.h>
26 #include <stdint.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <libintl.h>
30 #include <unistd.h>
31 #include <fcntl.h>
32 #include <sys/types.h>
33 #include <sys/stat.h>
34
35 #include "bblk_einfo.h"
36 #include "boot_utils.h"
37
38 bblk_hash_t bblk_no_hash = {BBLK_NO_HASH, 0, "(no hash)", NULL};
39 bblk_hash_t bblk_md5_hash = {BBLK_HASH_MD5, 0x10, "MD5", md5_calc};
40
41 bblk_hash_t *bblk_hash_list[BBLK_HASH_TOT] = {
42 &bblk_no_hash,
43 &bblk_md5_hash
44 };
45
46 /*
47 * einfo_compare_dotted_version()
48 * Compares two strings with an arbitrary long number of dot-separated numbers.
49 * Returns: 0 - if the version numbers are equal
50 * 1 - if str1 version number is more recent than str2
51 * 2 - if str2 version number is more recent than str1
52 * -1 - if an error occurred
53 *
54 * Comparison is done field by field, by retrieving an unsigned integer value,
55 * (missing fields are assumed as 0, but explict zeroes take precedence) so:
56 * 4.1.2.11 > 4.1.2.2 > 4.1.2.0 > 4.1.2
57 *
58 * where ">" means "more recent than".
59 */
60 static int
einfo_compare_dotted_version(const char * str1,const char * str2)61 einfo_compare_dotted_version(const char *str1, const char *str2)
62 {
63 int retval = 0;
64 char *verstr1, *verstr2, *freeptr1, *freeptr2;
65 char *parsep1, *parsep2;
66 unsigned int val_str1, val_str2;
67
68 freeptr1 = verstr1 = strdup(str1);
69 freeptr2 = verstr2 = strdup(str2);
70 if (verstr1 == NULL || verstr2 == NULL) {
71 retval = -1;
72 goto out;
73 }
74
75 while (verstr1 != NULL && verstr2 != NULL) {
76 parsep1 = strsep(&verstr1, ".");
77 parsep2 = strsep(&verstr2, ".");
78
79 val_str1 = atoi(parsep1);
80 val_str2 = atoi(parsep2);
81
82 if (val_str1 > val_str2) {
83 retval = 1;
84 goto out;
85 }
86
87 if (val_str2 > val_str1) {
88 retval = 2;
89 goto out;
90 }
91 }
92
93 /* Common portion of the version string is equal. */
94 if (verstr1 == NULL && verstr2 != NULL)
95 retval = 2;
96 if (verstr2 == NULL && verstr1 != NULL)
97 retval = 1;
98
99 out:
100 free(freeptr1);
101 free(freeptr2);
102 return (retval);
103 }
104
105 /*
106 * einfo_compare_timestamps()
107 * Currently, timestamp is in %Y%m%dT%H%M%SZ format in UTC, which means that
108 * we can simply do a lexicographic comparison to know which one is the most
109 * recent.
110 *
111 * Returns: 0 - if timestamps coincide
112 * 1 - if the timestamp in str1 is more recent
113 * 2 - if the timestamp in str2 is more recent
114 */
115 static int
einfo_compare_timestamps(const char * str1,const char * str2)116 einfo_compare_timestamps(const char *str1, const char *str2)
117 {
118 int retval;
119
120 retval = strcmp(str1, str2);
121 if (retval > 0)
122 retval = 1;
123 if (retval < 0)
124 retval = 2;
125
126 return (retval);
127 }
128
129 /*
130 * einfo_compare_version()
131 * Given two extended versions, compare the two and returns which one is more
132 * "recent". Comparison is based on dotted version number fields and a
133 * timestamp.
134 *
135 * Returns: -1 - on error
136 * 0 - if the two versions coincide
137 * 1 - if the version in str1 is more recent
138 * 2 - if the version in str2 is more recent
139 *
140 * The version string generally uses following form:
141 * self_release,build_release:timestamp
142 * The release numbers are compared as dotted versions.
143 *
144 * While comparing, if the self releases are identical but the build
145 * release is missing, this version string is considered older.
146 *
147 * If the release strings are identical, and one of the timestamps is missing,
148 * we return an error. Otherwise, return the result from comparing the
149 * timestamps.
150 */
151 static int
einfo_compare_version(const char * str1,const char * str2)152 einfo_compare_version(const char *str1, const char *str2)
153 {
154 int retval = 0;
155 char *verstr1, *verstr2, *freeptr1, *freeptr2;
156 char *parsep1, *parsep2;
157 char *timep1, *timep2;
158
159 freeptr1 = verstr1 = strdup(str1);
160 freeptr2 = verstr2 = strdup(str2);
161 if (verstr1 == NULL || verstr2 == NULL) {
162 retval = -1;
163 goto out;
164 }
165
166 /* Extract the time part from the version string. */
167 timep1 = verstr1;
168 timep2 = verstr2;
169 parsep1 = strsep(&timep1, ":");
170 parsep2 = strsep(&timep2, ":");
171
172 while (parsep1 != NULL && parsep2 != NULL) {
173 parsep1 = strsep(&verstr1, ",-");
174 parsep2 = strsep(&verstr2, ",-");
175
176 /* If both are NULL, compare timestamps */
177 if (parsep1 == NULL && parsep2 == NULL)
178 break;
179
180 if (parsep1 == NULL) {
181 retval = 2;
182 goto out;
183 }
184 if (parsep2 == NULL) {
185 retval = 1;
186 goto out;
187 }
188
189 retval = einfo_compare_dotted_version(parsep1, parsep2);
190 if (retval == 0)
191 continue;
192 else
193 goto out;
194 }
195
196 /* The dotted versions are identical, check timestamps. */
197 if (timep1 == NULL || timep2 == NULL) {
198 retval = -1;
199 goto out;
200 }
201 retval = einfo_compare_timestamps(timep1, timep2);
202 out:
203 free(freeptr1);
204 free(freeptr2);
205 return (retval);
206 }
207
208 /*
209 * print_einfo()
210 *
211 * Print the extended information contained into the pointed structure.
212 * 'bufsize' specifies the real size of the structure, since str_off and
213 * hash_off need to point somewhere past the header.
214 */
215 void
print_einfo(uint8_t flags,bblk_einfo_t * einfo,unsigned long bufsize)216 print_einfo(uint8_t flags, bblk_einfo_t *einfo, unsigned long bufsize)
217 {
218 int i = 0;
219 char *version;
220 boolean_t has_hash = B_FALSE;
221 unsigned char *hash = NULL;
222
223 if (einfo->str_off + einfo->str_size > bufsize) {
224 (void) fprintf(stdout, gettext("String offset %d is beyond the "
225 "buffer size\n"), einfo->str_off);
226 return;
227 }
228
229 version = (char *)einfo + einfo->str_off;
230 if (einfo->hash_type != BBLK_NO_HASH &&
231 einfo->hash_type < BBLK_HASH_TOT) {
232 if (einfo->hash_off + einfo->hash_size > bufsize) {
233 (void) fprintf(stdout, gettext("Warning: hashing "
234 "present but hash offset %d is beyond the buffer "
235 "size\n"), einfo->hash_off);
236 has_hash = B_FALSE;
237 } else {
238 hash = (unsigned char *)einfo + einfo->hash_off;
239 has_hash = B_TRUE;
240 }
241 }
242
243 if (flags & EINFO_PRINT_HEADER) {
244 (void) fprintf(stdout, "Boot Block Extended Info Header:\n");
245 (void) fprintf(stdout, "\tmagic: ");
246 for (i = 0; i < EINFO_MAGIC_SIZE; i++)
247 (void) fprintf(stdout, "%c", einfo->magic[i]);
248 (void) fprintf(stdout, "\n");
249 (void) fprintf(stdout, "\tversion: %d\n", einfo->version);
250 (void) fprintf(stdout, "\tflags: %x\n", einfo->flags);
251 (void) fprintf(stdout, "\textended version string offset: %d\n",
252 einfo->str_off);
253 (void) fprintf(stdout, "\textended version string size: %d\n",
254 einfo->str_size);
255 (void) fprintf(stdout, "\thashing type: %d (%s)\n",
256 einfo->hash_type, has_hash ?
257 bblk_hash_list[einfo->hash_type]->name : "nil");
258 (void) fprintf(stdout, "\thash offset: %d\n", einfo->hash_off);
259 (void) fprintf(stdout, "\thash size: %d\n", einfo->hash_size);
260 }
261
262 if (flags & EINFO_EASY_PARSE) {
263 (void) fprintf(stdout, "%s\n", version);
264 } else {
265 (void) fprintf(stdout, "Extended version string: %s\n",
266 version);
267 if (has_hash) {
268 (void) fprintf(stdout, "%s hash: ",
269 bblk_hash_list[einfo->hash_type]->name);
270 } else {
271 (void) fprintf(stdout, "No hashing available\n");
272 }
273 }
274
275 if (has_hash) {
276 for (i = 0; i < einfo->hash_size; i++) {
277 (void) fprintf(stdout, "%02x", hash[i]);
278 }
279 (void) fprintf(stdout, "\n");
280 }
281 }
282
283 static int
compute_hash(bblk_hs_t * hs,unsigned char * dest,bblk_hash_t * hash)284 compute_hash(bblk_hs_t *hs, unsigned char *dest, bblk_hash_t *hash)
285 {
286 if (hs == NULL || dest == NULL || hash == NULL)
287 return (-1);
288
289 hash->compute_hash(dest, hs->src_buf, hs->src_size);
290 return (0);
291 }
292
293 int
prepare_and_write_einfo(unsigned char * dest,char * infostr,bblk_hs_t * hs,uint32_t maxsize,uint32_t * used_space)294 prepare_and_write_einfo(unsigned char *dest, char *infostr, bblk_hs_t *hs,
295 uint32_t maxsize, uint32_t *used_space)
296 {
297 uint16_t hash_size;
298 uint32_t hash_off;
299 unsigned char *data;
300 bblk_einfo_t *einfo = (bblk_einfo_t *)dest;
301 bblk_hash_t *hashinfo = bblk_hash_list[BBLK_DEFAULT_HASH];
302
303 /*
304 * 'dest' might be both containing the buffer we want to hash and
305 * containing our einfo structure: delay any update of it after the
306 * hashing has been calculated.
307 */
308 hash_size = hashinfo->size;
309 hash_off = sizeof (bblk_einfo_t);
310
311 if (hash_off + hash_size > maxsize) {
312 (void) fprintf(stderr, gettext("Unable to add extended info, "
313 "not enough space\n"));
314 return (-1);
315 }
316
317 data = dest + hash_off;
318 if (compute_hash(hs, data, hashinfo) < 0) {
319 (void) fprintf(stderr, gettext("%s hash operation failed\n"),
320 hashinfo->name);
321 einfo->hash_type = bblk_no_hash.type;
322 einfo->hash_size = bblk_no_hash.size;
323 } else {
324 einfo->hash_type = hashinfo->type;
325 einfo->hash_size = hashinfo->size;
326 }
327
328 (void) memcpy(einfo->magic, EINFO_MAGIC, EINFO_MAGIC_SIZE);
329 einfo->version = BBLK_EINFO_VERSION;
330 einfo->flags = 0;
331 einfo->hash_off = hash_off;
332 einfo->hash_size = hash_size;
333 einfo->str_off = einfo->hash_off + einfo->hash_size + 1;
334
335 if (infostr == NULL) {
336 (void) fprintf(stderr, gettext("Unable to add extended info, "
337 "string is empty\n"));
338 return (-1);
339 }
340 einfo->str_size = strlen(infostr);
341
342 if (einfo->str_off + einfo->str_size > maxsize) {
343 (void) fprintf(stderr, gettext("Unable to add extended info, "
344 "not enough space\n"));
345 return (-1);
346 }
347
348 data = dest + einfo->str_off;
349 (void) memcpy(data, infostr, einfo->str_size);
350 *used_space = einfo->str_off + einfo->str_size;
351
352 return (0);
353 }
354
355 /*
356 * einfo_should_update()
357 * Given information on the boot block currently on disk (disk_einfo) and
358 * information on the supplied boot block (hs for hashing, verstr as the
359 * associated version string) decide if an update of the on-disk boot block
360 * is necessary or not.
361 */
362 boolean_t
einfo_should_update(bblk_einfo_t * disk_einfo,bblk_hs_t * hs,char * verstr)363 einfo_should_update(bblk_einfo_t *disk_einfo, bblk_hs_t *hs, char *verstr)
364 {
365 bblk_hash_t *hashing;
366 unsigned char *disk_hash;
367 unsigned char *local_hash;
368 char *disk_version;
369 int retval;
370
371 if (disk_einfo == NULL)
372 return (B_TRUE);
373
374 if (memcmp(disk_einfo->magic, EINFO_MAGIC, EINFO_MAGIC_SIZE) != 0)
375 return (B_TRUE);
376
377 if (disk_einfo->version < BBLK_EINFO_VERSION)
378 return (B_TRUE);
379
380 disk_version = einfo_get_string(disk_einfo);
381 retval = einfo_compare_version(verstr, disk_version);
382 /*
383 * If something goes wrong or if the on-disk version is more recent
384 * do not update the bootblock.
385 */
386 if (retval == -1 || retval == 2)
387 return (B_FALSE);
388
389 /*
390 * If we got here it means that the two version strings are either
391 * equal or the new bootblk binary is more recent. In order to save
392 * some needless writes let's use the hash to determine if an update
393 * is really necessary.
394 */
395 if (disk_einfo->hash_type == bblk_no_hash.type)
396 return (B_TRUE);
397
398 if (disk_einfo->hash_type >= BBLK_HASH_TOT)
399 return (B_TRUE);
400
401 hashing = bblk_hash_list[disk_einfo->hash_type];
402
403 local_hash = malloc(hashing->size);
404 if (local_hash == NULL)
405 return (B_TRUE);
406
407 /*
408 * Failure in computing the hash may mean something wrong
409 * with the boot block file. Better be conservative here.
410 */
411 if (compute_hash(hs, local_hash, hashing) < 0) {
412 free(local_hash);
413 return (B_FALSE);
414 }
415
416 disk_hash = (unsigned char *)einfo_get_hash(disk_einfo);
417
418 if (memcmp(local_hash, disk_hash, disk_einfo->hash_size) == 0) {
419 free(local_hash);
420 return (B_FALSE);
421 }
422
423 free(local_hash);
424 return (B_TRUE);
425 }
426
427 char *
einfo_get_string(bblk_einfo_t * einfo)428 einfo_get_string(bblk_einfo_t *einfo)
429 {
430 if (einfo == NULL)
431 return (NULL);
432
433 return ((char *)einfo + einfo->str_off);
434 }
435
436 char *
einfo_get_hash(bblk_einfo_t * einfo)437 einfo_get_hash(bblk_einfo_t *einfo)
438 {
439 if (einfo == NULL)
440 return (NULL);
441
442 return ((char *)einfo + einfo->hash_off);
443 }
444