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/param.h>
28 #include <sys/gpt.h>
29
30 #ifndef LITTLE_ENDIAN
31 #error gpt.c works only for little endian architectures
32 #endif
33
34 #include "stand.h"
35 #include "zlib.h"
36 #include "drv.h"
37 #include "gpt.h"
38
39 static struct gpt_hdr hdr_primary, hdr_backup, *gpthdr;
40 static uint64_t hdr_primary_lba, hdr_backup_lba;
41 static struct gpt_ent table_primary[MAXTBLENTS], table_backup[MAXTBLENTS];
42 static struct gpt_ent *gpttable;
43 static int curent, bootonce;
44
45 /*
46 * Buffer below 64kB passed on gptread(), which can hold at least
47 * one sector of data (512 bytes).
48 */
49 static char *secbuf;
50
51 static void
gptupdate(const char * which,struct dsk * dskp,struct gpt_hdr * hdr,struct gpt_ent * table)52 gptupdate(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
53 struct gpt_ent *table)
54 {
55 int entries_per_sec, firstent;
56 daddr_t slba;
57
58 /*
59 * We need to update the following for both primary and backup GPT:
60 * 1. Sector on disk that contains current partition.
61 * 2. Partition table checksum.
62 * 3. Header checksum.
63 * 4. Header on disk.
64 */
65
66 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
67 slba = curent / entries_per_sec;
68 firstent = slba * entries_per_sec;
69 bcopy(&table[firstent], secbuf, DEV_BSIZE);
70 slba += hdr->hdr_lba_table;
71 if (drvwrite(dskp, secbuf, slba, 1)) {
72 printf("%s: unable to update %s GPT partition table\n",
73 BOOTPROG, which);
74 return;
75 }
76 hdr->hdr_crc_table = crc32(0, Z_NULL, 0);
77 hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, (const Bytef *)table,
78 hdr->hdr_entries * hdr->hdr_entsz);
79 hdr->hdr_crc_self = crc32(0, Z_NULL, 0);
80 hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, (const Bytef *)hdr,
81 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 = crc32(0, Z_NULL, 0);
202 if (crc32(hdr->hdr_crc_self, (const Bytef *)hdr, hdr->hdr_size) !=
203 crc) {
204 printf("%s: %s GPT header checksum mismatch\n", BOOTPROG,
205 which);
206 return (-1);
207 }
208 hdr->hdr_crc_self = crc;
209 return (0);
210 }
211
212 void
gptbootfailed(struct dsk * dskp)213 gptbootfailed(struct dsk *dskp)
214 {
215
216 if (!(gpttable[curent].ent_attr & GPT_ENT_ATTR_BOOTONCE))
217 return;
218
219 if (hdr_primary_lba > 0) {
220 table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
221 table_primary[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
222 gptupdate("primary", dskp, &hdr_primary, table_primary);
223 }
224 if (hdr_backup_lba > 0) {
225 table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
226 table_backup[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
227 gptupdate("backup", dskp, &hdr_backup, table_backup);
228 }
229 }
230
231 static void
gptbootconv(const char * which,struct dsk * dskp,struct gpt_hdr * hdr,struct gpt_ent * table)232 gptbootconv(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
233 struct gpt_ent *table)
234 {
235 struct gpt_ent *ent;
236 daddr_t slba;
237 int table_updated, sector_updated;
238 int entries_per_sec, nent, part;
239
240 table_updated = 0;
241 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
242 for (nent = 0, slba = hdr->hdr_lba_table;
243 slba < hdr->hdr_lba_table + hdr->hdr_entries / entries_per_sec;
244 slba++, nent += entries_per_sec) {
245 sector_updated = 0;
246 for (part = 0; part < entries_per_sec; part++) {
247 ent = &table[nent + part];
248 if ((ent->ent_attr & (GPT_ENT_ATTR_BOOTME |
249 GPT_ENT_ATTR_BOOTONCE |
250 GPT_ENT_ATTR_BOOTFAILED)) !=
251 GPT_ENT_ATTR_BOOTONCE) {
252 continue;
253 }
254 ent->ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
255 ent->ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
256 table_updated = 1;
257 sector_updated = 1;
258 }
259 if (!sector_updated)
260 continue;
261 bcopy(&table[nent], secbuf, DEV_BSIZE);
262 if (drvwrite(dskp, secbuf, slba, 1)) {
263 printf("%s: unable to update %s GPT partition table\n",
264 BOOTPROG, which);
265 }
266 }
267 if (!table_updated)
268 return;
269 hdr->hdr_crc_table = crc32(0, Z_NULL, 0);
270 hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, (const Bytef *)table,
271 hdr->hdr_entries * hdr->hdr_entsz);
272 hdr->hdr_crc_self = crc32(0, Z_NULL, 0);
273 hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, (const Bytef *)hdr,
274 hdr->hdr_size);
275 bzero(secbuf, DEV_BSIZE);
276 bcopy(hdr, secbuf, hdr->hdr_size);
277 if (drvwrite(dskp, secbuf, hdr->hdr_lba_self, 1))
278 printf("%s: unable to update %s GPT header\n", BOOTPROG, which);
279 }
280
281 static int
gptread_table(const char * which,struct dsk * dskp,struct gpt_hdr * hdr,struct gpt_ent * table)282 gptread_table(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
283 struct gpt_ent *table)
284 {
285 struct gpt_ent *ent;
286 int entries_per_sec;
287 int part, nent;
288 daddr_t slba;
289
290 if (hdr->hdr_entries == 0)
291 return (0);
292
293 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
294 slba = hdr->hdr_lba_table;
295 nent = 0;
296 for (;;) {
297 if (drvread(dskp, secbuf, slba, 1)) {
298 printf("%s: unable to read %s GPT partition table\n",
299 BOOTPROG, which);
300 return (-1);
301 }
302 ent = (struct gpt_ent *)secbuf;
303 for (part = 0; part < entries_per_sec; part++, ent++) {
304 bcopy(ent, &table[nent], sizeof(table[nent]));
305 if (++nent >= hdr->hdr_entries)
306 break;
307 }
308 if (nent >= hdr->hdr_entries)
309 break;
310 slba++;
311 }
312 if (crc32(0, (const Bytef *)table, nent * hdr->hdr_entsz) !=
313 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(struct dsk * dskp,char * buf)321 gptread(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", dskp, &hdr_primary, table_primary) == 0) {
337 hdr_primary_lba = hdr_primary.hdr_lba_self;
338 gpthdr = &hdr_primary;
339 gpttable = table_primary;
340 }
341
342 if (hdr_primary_lba > 0) {
343 /*
344 * If primary header is valid, we can get backup
345 * header location from there.
346 */
347 altlba = hdr_primary.hdr_lba_alt;
348 } else {
349 altlba = drvsize(dskp);
350 if (altlba > 0)
351 altlba--;
352 }
353 if (altlba == 0)
354 printf("%s: unable to locate backup GPT header\n", BOOTPROG);
355 else if (gptread_hdr("backup", dskp, &hdr_backup, altlba) == 0 &&
356 gptread_table("backup", dskp, &hdr_backup, table_backup) == 0) {
357 hdr_backup_lba = hdr_backup.hdr_lba_self;
358 if (hdr_primary_lba == 0) {
359 gpthdr = &hdr_backup;
360 gpttable = table_backup;
361 printf("%s: using backup GPT\n", BOOTPROG);
362 }
363 }
364
365 /*
366 * Convert all BOOTONCE without BOOTME flags into BOOTFAILED.
367 * BOOTONCE without BOOTME means that we tried to boot from it,
368 * but failed after leaving gptboot and machine was rebooted.
369 * We don't want to leave partitions marked as BOOTONCE only,
370 * because when we boot successfully start-up scripts should
371 * find at most one partition with only BOOTONCE flag and this
372 * will mean that we booted from that partition.
373 */
374 if (hdr_primary_lba != 0)
375 gptbootconv("primary", dskp, &hdr_primary, table_primary);
376 if (hdr_backup_lba != 0)
377 gptbootconv("backup", dskp, &hdr_backup, table_backup);
378
379 if (hdr_primary_lba == 0 && hdr_backup_lba == 0)
380 return (-1);
381 return (0);
382 }
383