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 __FBSDID("$FreeBSD: stable/12/stand/libsa/gpt.c 370826 2021-10-17 18:46:07Z kevans $");
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 "zlib.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(0, Z_NULL, 0);
80 hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, (const Bytef *)table,
81 hdr->hdr_entries * hdr->hdr_entsz);
82 hdr->hdr_crc_self = crc32(0, Z_NULL, 0);;
83 hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, (const Bytef *)hdr,
84 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, (const Bytef *)hdr, hdr->hdr_size) !=
206 crc) {
207 printf("%s: %s GPT header checksum mismatch\n", BOOTPROG,
208 which);
209 return (-1);
210 }
211 hdr->hdr_crc_self = crc;
212 return (0);
213 }
214
215 void
gptbootfailed(struct dsk * dskp)216 gptbootfailed(struct dsk *dskp)
217 {
218
219 if (!(gpttable[curent].ent_attr & GPT_ENT_ATTR_BOOTONCE))
220 return;
221
222 if (hdr_primary_lba > 0) {
223 table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
224 table_primary[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
225 gptupdate("primary", dskp, &hdr_primary, table_primary);
226 }
227 if (hdr_backup_lba > 0) {
228 table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
229 table_backup[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
230 gptupdate("backup", dskp, &hdr_backup, table_backup);
231 }
232 }
233
234 static void
gptbootconv(const char * which,struct dsk * dskp,struct gpt_hdr * hdr,struct gpt_ent * table)235 gptbootconv(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
236 struct gpt_ent *table)
237 {
238 struct gpt_ent *ent;
239 daddr_t slba;
240 int table_updated, sector_updated;
241 int entries_per_sec, nent, part;
242
243 table_updated = 0;
244 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
245 for (nent = 0, slba = hdr->hdr_lba_table;
246 slba < hdr->hdr_lba_table + hdr->hdr_entries / entries_per_sec;
247 slba++, nent += entries_per_sec) {
248 sector_updated = 0;
249 for (part = 0; part < entries_per_sec; part++) {
250 ent = &table[nent + part];
251 if ((ent->ent_attr & (GPT_ENT_ATTR_BOOTME |
252 GPT_ENT_ATTR_BOOTONCE |
253 GPT_ENT_ATTR_BOOTFAILED)) !=
254 GPT_ENT_ATTR_BOOTONCE) {
255 continue;
256 }
257 ent->ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
258 ent->ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
259 table_updated = 1;
260 sector_updated = 1;
261 }
262 if (!sector_updated)
263 continue;
264 bcopy(&table[nent], secbuf, DEV_BSIZE);
265 if (drvwrite(dskp, secbuf, slba, 1)) {
266 printf("%s: unable to update %s GPT partition table\n",
267 BOOTPROG, which);
268 }
269 }
270 if (!table_updated)
271 return;
272 hdr->hdr_crc_table = crc32(0, Z_NULL, 0);
273 hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, (const Bytef *)table,
274 hdr->hdr_entries * hdr->hdr_entsz);
275 hdr->hdr_crc_self = crc32(0, Z_NULL, 0);
276 hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, (const Bytef *)hdr,
277 hdr->hdr_size);
278 bzero(secbuf, DEV_BSIZE);
279 bcopy(hdr, secbuf, hdr->hdr_size);
280 if (drvwrite(dskp, secbuf, hdr->hdr_lba_self, 1))
281 printf("%s: unable to update %s GPT header\n", BOOTPROG, which);
282 }
283
284 static int
gptread_table(const char * which,struct dsk * dskp,struct gpt_hdr * hdr,struct gpt_ent * table)285 gptread_table(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
286 struct gpt_ent *table)
287 {
288 struct gpt_ent *ent;
289 int entries_per_sec;
290 int part, nent;
291 daddr_t slba;
292
293 if (hdr->hdr_entries == 0)
294 return (0);
295
296 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
297 slba = hdr->hdr_lba_table;
298 nent = 0;
299 for (;;) {
300 if (drvread(dskp, secbuf, slba, 1)) {
301 printf("%s: unable to read %s GPT partition table\n",
302 BOOTPROG, which);
303 return (-1);
304 }
305 ent = (struct gpt_ent *)secbuf;
306 for (part = 0; part < entries_per_sec; part++, ent++) {
307 bcopy(ent, &table[nent], sizeof(table[nent]));
308 if (++nent >= hdr->hdr_entries)
309 break;
310 }
311 if (nent >= hdr->hdr_entries)
312 break;
313 slba++;
314 }
315 if (crc32(0, (const Bytef *)table, nent * hdr->hdr_entsz) !=
316 hdr->hdr_crc_table) {
317 printf("%s: %s GPT table checksum mismatch\n", BOOTPROG, which);
318 return (-1);
319 }
320 return (0);
321 }
322
323 int
gptread(struct dsk * dskp,char * buf)324 gptread(struct dsk *dskp, char *buf)
325 {
326 uint64_t altlba;
327
328 /*
329 * Read and verify both GPT headers: primary and backup.
330 */
331
332 secbuf = buf;
333 hdr_primary_lba = hdr_backup_lba = 0;
334 curent = -1;
335 bootonce = 1;
336 dskp->start = 0;
337
338 if (gptread_hdr("primary", dskp, &hdr_primary, 1) == 0 &&
339 gptread_table("primary", dskp, &hdr_primary, table_primary) == 0) {
340 hdr_primary_lba = hdr_primary.hdr_lba_self;
341 gpthdr = &hdr_primary;
342 gpttable = table_primary;
343 }
344
345 if (hdr_primary_lba > 0) {
346 /*
347 * If primary header is valid, we can get backup
348 * header location from there.
349 */
350 altlba = hdr_primary.hdr_lba_alt;
351 } else {
352 altlba = drvsize(dskp);
353 if (altlba > 0)
354 altlba--;
355 }
356 if (altlba == 0)
357 printf("%s: unable to locate backup GPT header\n", BOOTPROG);
358 else if (gptread_hdr("backup", dskp, &hdr_backup, altlba) == 0 &&
359 gptread_table("backup", dskp, &hdr_backup, table_backup) == 0) {
360 hdr_backup_lba = hdr_backup.hdr_lba_self;
361 if (hdr_primary_lba == 0) {
362 gpthdr = &hdr_backup;
363 gpttable = table_backup;
364 printf("%s: using backup GPT\n", BOOTPROG);
365 }
366 }
367
368 /*
369 * Convert all BOOTONCE without BOOTME flags into BOOTFAILED.
370 * BOOTONCE without BOOTME means that we tried to boot from it,
371 * but failed after leaving gptboot and machine was rebooted.
372 * We don't want to leave partitions marked as BOOTONCE only,
373 * because when we boot successfully start-up scripts should
374 * find at most one partition with only BOOTONCE flag and this
375 * will mean that we booted from that partition.
376 */
377 if (hdr_primary_lba != 0)
378 gptbootconv("primary", dskp, &hdr_primary, table_primary);
379 if (hdr_backup_lba != 0)
380 gptbootconv("backup", dskp, &hdr_backup, table_backup);
381
382 if (hdr_primary_lba == 0 && hdr_backup_lba == 0)
383 return (-1);
384 return (0);
385 }
386