1 /*
2 * Copyright (c) 2010 Pawel Jakub Dawidek <pjd@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 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28
29 #include <sys/param.h>
30 #include <sys/gpt.h>
31
32 #ifndef LITTLE_ENDIAN
33 #error gpt.c works only for little endian architectures
34 #endif
35
36 #include "zlib.h"
37 #include "drv.h"
38 #include "util.h"
39 #include "gpt.h"
40
41 #define MAXTBLENTS 128
42
43 static struct gpt_hdr hdr_primary, hdr_backup, *gpthdr;
44 static uint64_t hdr_primary_lba, hdr_backup_lba;
45 static struct gpt_ent table_primary[MAXTBLENTS], table_backup[MAXTBLENTS];
46 static struct gpt_ent *gpttable;
47 static int curent, bootonce;
48
49 /*
50 * Buffer below 64kB passed on gptread(), which can hold at least
51 * one sector of data (512 bytes).
52 */
53 static char *secbuf;
54
55 static void
gptupdate(const char * which,struct dsk * dskp,struct gpt_hdr * hdr,struct gpt_ent * table)56 gptupdate(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
57 struct gpt_ent *table)
58 {
59 int entries_per_sec, firstent;
60 daddr_t slba;
61
62 /*
63 * We need to update the following for both primary and backup GPT:
64 * 1. Sector on disk that contains current partition.
65 * 2. Partition table checksum.
66 * 3. Header checksum.
67 * 4. Header on disk.
68 */
69
70 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
71 slba = curent / entries_per_sec;
72 firstent = slba * entries_per_sec;
73 bcopy(&table[firstent], secbuf, DEV_BSIZE);
74 slba += hdr->hdr_lba_table;
75 if (drvwrite(dskp, secbuf, slba, 1)) {
76 printf("%s: unable to update %s GPT partition table\n",
77 BOOTPROG, which);
78 return;
79 }
80 hdr->hdr_crc_table = crc32(0, Z_NULL, 0);
81 hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, table,
82 hdr->hdr_entries * hdr->hdr_entsz);
83 hdr->hdr_crc_self = crc32(0, Z_NULL, 0);
84 hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, hdr, hdr->hdr_size);
85 bzero(secbuf, DEV_BSIZE);
86 bcopy(hdr, secbuf, hdr->hdr_size);
87 if (drvwrite(dskp, secbuf, hdr->hdr_lba_self, 1)) {
88 printf("%s: unable to update %s GPT header\n", BOOTPROG, which);
89 return;
90 }
91 }
92
93 int
gptfind(const uuid_t * uuid,struct dsk * dskp,int part)94 gptfind(const uuid_t *uuid, struct dsk *dskp, int part)
95 {
96 struct gpt_ent *ent;
97 int firsttry;
98
99 if (part >= 0) {
100 if (part == 0 || part > gpthdr->hdr_entries) {
101 printf("%s: invalid partition index\n", BOOTPROG);
102 return (-1);
103 }
104 ent = &gpttable[part - 1];
105 if (bcmp(&ent->ent_type, uuid, sizeof (uuid_t)) != 0) {
106 printf("%s: specified partition is not UFS\n",
107 BOOTPROG);
108 return (-1);
109 }
110 curent = part - 1;
111 goto found;
112 }
113
114 firsttry = (curent == -1);
115 curent++;
116 if (curent >= gpthdr->hdr_entries) {
117 curent = gpthdr->hdr_entries;
118 return (-1);
119 }
120 if (bootonce) {
121 /*
122 * First look for partition with both GPT_ENT_ATTR_BOOTME and
123 * GPT_ENT_ATTR_BOOTONCE flags.
124 */
125 for (; curent < gpthdr->hdr_entries; curent++) {
126 ent = &gpttable[curent];
127 if (bcmp(&ent->ent_type, uuid, sizeof (uuid_t)) != 0)
128 continue;
129 if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTME))
130 continue;
131 if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTONCE))
132 continue;
133 /* Ok, found one. */
134 goto found;
135 }
136 bootonce = 0;
137 curent = 0;
138 }
139 for (; curent < gpthdr->hdr_entries; curent++) {
140 ent = &gpttable[curent];
141 if (bcmp(&ent->ent_type, uuid, sizeof (uuid_t)) != 0)
142 continue;
143 if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTME))
144 continue;
145 if (ent->ent_attr & GPT_ENT_ATTR_BOOTONCE)
146 continue;
147 /* Ok, found one. */
148 goto found;
149 }
150 if (firsttry) {
151 /*
152 * No partition with BOOTME flag was found, try to boot from
153 * first UFS partition.
154 */
155 for (curent = 0; curent < gpthdr->hdr_entries; curent++) {
156 ent = &gpttable[curent];
157 if (bcmp(&ent->ent_type, uuid, sizeof (uuid_t)) != 0)
158 continue;
159 /* Ok, found one. */
160 goto found;
161 }
162 }
163 return (-1);
164 found:
165 dskp->part = curent + 1;
166 ent = &gpttable[curent];
167 dskp->start = ent->ent_lba_start;
168 if (ent->ent_attr & GPT_ENT_ATTR_BOOTONCE) {
169 /*
170 * Clear BOOTME, but leave BOOTONCE set before trying to
171 * boot from this partition.
172 */
173 if (hdr_primary_lba > 0) {
174 table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTME;
175 gptupdate("primary", dskp, &hdr_primary, table_primary);
176 }
177 if (hdr_backup_lba > 0) {
178 table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTME;
179 gptupdate("backup", dskp, &hdr_backup, table_backup);
180 }
181 }
182 return (0);
183 }
184
185 static int
gptread_hdr(const char * which,struct dsk * dskp,struct gpt_hdr * hdr,uint64_t hdrlba)186 gptread_hdr(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
187 uint64_t hdrlba)
188 {
189 uint32_t crc;
190
191 if (drvread(dskp, secbuf, hdrlba, 1)) {
192 printf("%s: unable to read %s GPT header\n", BOOTPROG, which);
193 return (-1);
194 }
195 bcopy(secbuf, hdr, sizeof (*hdr));
196 if (bcmp(hdr->hdr_sig, GPT_HDR_SIG, sizeof (hdr->hdr_sig)) != 0 ||
197 hdr->hdr_lba_self != hdrlba || hdr->hdr_revision < 0x00010000 ||
198 hdr->hdr_entsz < sizeof (struct gpt_ent) ||
199 hdr->hdr_entries > MAXTBLENTS || DEV_BSIZE % hdr->hdr_entsz != 0) {
200 printf("%s: invalid %s GPT header\n", BOOTPROG, which);
201 return (-1);
202 }
203 crc = hdr->hdr_crc_self;
204 hdr->hdr_crc_self = crc32(0, Z_NULL, 0);
205 if (crc32(hdr->hdr_crc_self, hdr, hdr->hdr_size) != crc) {
206 printf("%s: %s GPT header checksum mismatch\n", BOOTPROG,
207 which);
208 return (-1);
209 }
210 hdr->hdr_crc_self = crc;
211 return (0);
212 }
213
214 void
gptbootfailed(struct dsk * dskp)215 gptbootfailed(struct dsk *dskp)
216 {
217
218 if (!(gpttable[curent].ent_attr & GPT_ENT_ATTR_BOOTONCE))
219 return;
220
221 if (hdr_primary_lba > 0) {
222 table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
223 table_primary[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
224 gptupdate("primary", dskp, &hdr_primary, table_primary);
225 }
226 if (hdr_backup_lba > 0) {
227 table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
228 table_backup[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
229 gptupdate("backup", dskp, &hdr_backup, table_backup);
230 }
231 }
232
233 static void
gptbootconv(const char * which,struct dsk * dskp,struct gpt_hdr * hdr,struct gpt_ent * table)234 gptbootconv(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
235 struct gpt_ent *table)
236 {
237 struct gpt_ent *ent;
238 daddr_t slba;
239 int table_updated, sector_updated;
240 int entries_per_sec, nent, part;
241
242 table_updated = 0;
243 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
244 for (nent = 0, slba = hdr->hdr_lba_table;
245 slba < hdr->hdr_lba_table + hdr->hdr_entries / entries_per_sec;
246 slba++, nent += entries_per_sec) {
247 sector_updated = 0;
248 for (part = 0; part < entries_per_sec; part++) {
249 ent = &table[nent + part];
250 if ((ent->ent_attr & (GPT_ENT_ATTR_BOOTME |
251 GPT_ENT_ATTR_BOOTONCE |
252 GPT_ENT_ATTR_BOOTFAILED)) !=
253 GPT_ENT_ATTR_BOOTONCE) {
254 continue;
255 }
256 ent->ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
257 ent->ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
258 table_updated = 1;
259 sector_updated = 1;
260 }
261 if (!sector_updated)
262 continue;
263 bcopy(&table[nent], secbuf, DEV_BSIZE);
264 if (drvwrite(dskp, secbuf, slba, 1)) {
265 printf("%s: unable to update %s GPT partition table\n",
266 BOOTPROG, which);
267 }
268 }
269 if (!table_updated)
270 return;
271 hdr->hdr_crc_table = crc32(0, Z_NULL, 0);
272 hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, table,
273 hdr->hdr_entries * hdr->hdr_entsz);
274 hdr->hdr_crc_self = crc32(0, Z_NULL, 0);
275 hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, hdr, hdr->hdr_size);
276 bzero(secbuf, DEV_BSIZE);
277 bcopy(hdr, secbuf, hdr->hdr_size);
278 if (drvwrite(dskp, secbuf, hdr->hdr_lba_self, 1))
279 printf("%s: unable to update %s GPT header\n", BOOTPROG, which);
280 }
281
282 static int
gptread_table(const char * which,const uuid_t * uuid,struct dsk * dskp,struct gpt_hdr * hdr,struct gpt_ent * table)283 gptread_table(const char *which, const uuid_t *uuid, struct dsk *dskp,
284 struct gpt_hdr *hdr, struct gpt_ent *table)
285 {
286 struct gpt_ent *ent;
287 int entries_per_sec;
288 int part, nent;
289 daddr_t slba;
290
291 if (hdr->hdr_entries == 0)
292 return (0);
293
294 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
295 slba = hdr->hdr_lba_table;
296 nent = 0;
297 for (;;) {
298 if (drvread(dskp, secbuf, slba, 1)) {
299 printf("%s: unable to read %s GPT partition table\n",
300 BOOTPROG, which);
301 return (-1);
302 }
303 ent = (struct gpt_ent *)secbuf;
304 for (part = 0; part < entries_per_sec; part++, ent++) {
305 bcopy(ent, &table[nent], sizeof (table[nent]));
306 if (++nent >= hdr->hdr_entries)
307 break;
308 }
309 if (nent >= hdr->hdr_entries)
310 break;
311 slba++;
312 }
313 if (crc32(0, table, nent * hdr->hdr_entsz) != hdr->hdr_crc_table) {
314 printf("%s: %s GPT table checksum mismatch\n", BOOTPROG, which);
315 return (-1);
316 }
317 return (0);
318 }
319
320 int
gptread(const uuid_t * uuid,struct dsk * dskp,char * buf)321 gptread(const uuid_t *uuid, struct dsk *dskp, char *buf)
322 {
323 uint64_t altlba;
324
325 /*
326 * Read and verify both GPT headers: primary and backup.
327 */
328
329 secbuf = buf;
330 hdr_primary_lba = hdr_backup_lba = 0;
331 curent = -1;
332 bootonce = 1;
333 dskp->start = 0;
334
335 if (gptread_hdr("primary", dskp, &hdr_primary, 1) == 0 &&
336 gptread_table("primary", uuid, dskp, &hdr_primary,
337 table_primary) == 0) {
338 hdr_primary_lba = hdr_primary.hdr_lba_self;
339 gpthdr = &hdr_primary;
340 gpttable = table_primary;
341 }
342
343 if (hdr_primary_lba > 0) {
344 /*
345 * If primary header is valid, we can get backup
346 * header location from there.
347 */
348 altlba = hdr_primary.hdr_lba_alt;
349 } else {
350 altlba = drvsize(dskp);
351 if (altlba > 0)
352 altlba--;
353 }
354 if (altlba == 0)
355 printf("%s: unable to locate backup GPT header\n", BOOTPROG);
356 else if (gptread_hdr("backup", dskp, &hdr_backup, altlba) == 0 &&
357 gptread_table("backup", uuid, dskp, &hdr_backup,
358 table_backup) == 0) {
359 hdr_backup_lba = hdr_backup.hdr_lba_self;
360 if (hdr_primary_lba == 0) {
361 gpthdr = &hdr_backup;
362 gpttable = table_backup;
363 printf("%s: using backup GPT\n", BOOTPROG);
364 }
365 }
366
367 /*
368 * Convert all BOOTONCE without BOOTME flags into BOOTFAILED.
369 * BOOTONCE without BOOTME means that we tried to boot from it,
370 * but failed after leaving gptboot and machine was rebooted.
371 * We don't want to leave partitions marked as BOOTONCE only,
372 * because when we boot successfully start-up scripts should
373 * find at most one partition with only BOOTONCE flag and this
374 * will mean that we booted from that partition.
375 */
376 if (hdr_primary_lba != 0)
377 gptbootconv("primary", dskp, &hdr_primary, table_primary);
378 if (hdr_backup_lba != 0)
379 gptbootconv("backup", dskp, &hdr_backup, table_backup);
380
381 if (hdr_primary_lba == 0 && hdr_backup_lba == 0)
382 return (-1);
383 return (0);
384 }
385