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