stand/libsa/gpt.c

   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 #include <sys/param.h>
  29 #include <sys/gpt.h>
  30
  31 #ifndef LITTLE_ENDIAN
  32 #error gpt.c works only for little endian architectures
  33 #endif
  34
  35 #include "stand.h"
  36 #include "zlib.h"
  37 #include "drv.h"
  38 #include "gpt.h"
  39
  40 static struct gpt_hdr hdr_primary, hdr_backup, *gpthdr;
  41 static uint64_t hdr_primary_lba, hdr_backup_lba;
  42 static struct gpt_ent table_primary[MAXTBLENTS], table_backup[MAXTBLENTS];
  43 static struct gpt_ent *gpttable;
  44 static int curent, bootonce;
  45
  46 /*
  47  * Buffer below 64kB passed on gptread(), which can hold at least
  48  * one sector of data (512 bytes).
  49  */
  50 static char *secbuf;
  51
  52 static void
  53 gptupdate(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
  54     struct gpt_ent *table)
  55 {
  56         int entries_per_sec, firstent;
  57         daddr_t slba;
  58
  59         /*
  60          * We need to update the following for both primary and backup GPT:
  61          * 1. Sector on disk that contains current partition.
  62          * 2. Partition table checksum.
  63          * 3. Header checksum.
  64          * 4. Header on disk.
  65          */
  66
  67         entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
  68         slba = curent / entries_per_sec;
  69         firstent = slba * entries_per_sec;
  70         bcopy(&table[firstent], secbuf, DEV_BSIZE);
  71         slba += hdr->hdr_lba_table;
  72         if (drvwrite(dskp, secbuf, slba, 1)) {
  73                 printf("%s: unable to update %s GPT partition table\n",
  74                     BOOTPROG, which);
  75                 return;
  76         }
  77         hdr->hdr_crc_table = crc32(0, Z_NULL, 0);
  78         hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, (const Bytef *)table,
  79             hdr->hdr_entries * hdr->hdr_entsz);
  80         hdr->hdr_crc_self = crc32(0, Z_NULL, 0);
  81         hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, (const Bytef *)hdr,
  82             hdr->hdr_size);
  83         bzero(secbuf, DEV_BSIZE);
  84         bcopy(hdr, secbuf, hdr->hdr_size);
  85         if (drvwrite(dskp, secbuf, hdr->hdr_lba_self, 1)) {
  86                 printf("%s: unable to update %s GPT header\n", BOOTPROG, which);
  87                 return;
  88         }
  89 }
  90
  91 int
  92 gptfind(const uuid_t *uuid, struct dsk *dskp, int part)
  93 {
  94         struct gpt_ent *ent;
  95         int firsttry;
  96
  97         if (part >= 0) {
  98                 if (part == 0 || part > gpthdr->hdr_entries) {
  99                         printf("%s: invalid partition index\n", BOOTPROG);
 100                         return (-1);
 101                 }
 102                 ent = &gpttable[part - 1];
 103                 if (bcmp(&ent->ent_type, uuid, sizeof(uuid_t)) != 0) {
 104                         printf("%s: specified partition is not UFS\n",
 105                             BOOTPROG);
 106                         return (-1);
 107                 }
 108                 curent = part - 1;
 109                 goto found;
 110         }
 111
 112         firsttry = (curent == -1);
 113         curent++;
 114         if (curent >= gpthdr->hdr_entries) {
 115                 curent = gpthdr->hdr_entries;
 116                 return (-1);
 117         }
 118         if (bootonce) {
 119                 /*
 120                  * First look for partition with both GPT_ENT_ATTR_BOOTME and
 121                  * GPT_ENT_ATTR_BOOTONCE flags.
 122                  */
 123                 for (; curent < gpthdr->hdr_entries; curent++) {
 124                         ent = &gpttable[curent];
 125                         if (bcmp(&ent->ent_type, uuid, sizeof(uuid_t)) != 0)
 126                                 continue;
 127                         if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTME))
 128                                 continue;
 129                         if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTONCE))
 130                                 continue;
 131                         /* Ok, found one. */
 132                         goto found;
 133                 }
 134                 bootonce = 0;
 135                 curent = 0;
 136         }
 137         for (; curent < gpthdr->hdr_entries; curent++) {
 138                 ent = &gpttable[curent];
 139                 if (bcmp(&ent->ent_type, uuid, sizeof(uuid_t)) != 0)
 140                         continue;
 141                 if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTME))
 142                         continue;
 143                 if (ent->ent_attr & GPT_ENT_ATTR_BOOTONCE)
 144                         continue;
 145                 /* Ok, found one. */
 146                 goto found;
 147         }
 148         if (firsttry) {
 149                 /*
 150                  * No partition with BOOTME flag was found, try to boot from
 151                  * first UFS partition.
 152                  */
 153                 for (curent = 0; curent < gpthdr->hdr_entries; curent++) {
 154                         ent = &gpttable[curent];
 155                         if (bcmp(&ent->ent_type, uuid, sizeof(uuid_t)) != 0)
 156                                 continue;
 157                         /* Ok, found one. */
 158                         goto found;
 159                 }
 160         }
 161         return (-1);
 162 found:
 163         dskp->part = curent + 1;
 164         ent = &gpttable[curent];
 165         dskp->start = ent->ent_lba_start;
 166         if (ent->ent_attr & GPT_ENT_ATTR_BOOTONCE) {
 167                 /*
 168                  * Clear BOOTME, but leave BOOTONCE set before trying to
 169                  * boot from this partition.
 170                  */
 171                 if (hdr_primary_lba > 0) {
 172                         table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTME;
 173                         gptupdate("primary", dskp, &hdr_primary, table_primary);
 174                 }
 175                 if (hdr_backup_lba > 0) {
 176                         table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTME;
 177                         gptupdate("backup", dskp, &hdr_backup, table_backup);
 178                 }
 179         }
 180         return (0);
 181 }
 182
 183 static int
 184 gptread_hdr(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
 185     uint64_t hdrlba)
 186 {
 187         uint32_t crc;
 188
 189         if (drvread(dskp, secbuf, hdrlba, 1)) {
 190                 printf("%s: unable to read %s GPT header\n", BOOTPROG, which);
 191                 return (-1);
 192         }
 193         bcopy(secbuf, hdr, sizeof(*hdr));
 194         if (bcmp(hdr->hdr_sig, GPT_HDR_SIG, sizeof(hdr->hdr_sig)) != 0 ||
 195             hdr->hdr_lba_self != hdrlba || hdr->hdr_revision < 0x00010000 ||
 196             hdr->hdr_entsz < sizeof(struct gpt_ent) ||
 197             hdr->hdr_entries > MAXTBLENTS || DEV_BSIZE % hdr->hdr_entsz != 0) {
 198                 printf("%s: invalid %s GPT header\n", BOOTPROG, which);
 199                 return (-1);
 200         }
 201         crc = hdr->hdr_crc_self;
 202         hdr->hdr_crc_self = crc32(0, Z_NULL, 0);
 203         if (crc32(hdr->hdr_crc_self, (const Bytef *)hdr, hdr->hdr_size) !=
 204             crc) {
 205                 printf("%s: %s GPT header checksum mismatch\n", BOOTPROG,
 206                     which);
 207                 return (-1);
 208         }
 209         hdr->hdr_crc_self = crc;
 210         return (0);
 211 }
 212
 213 void
 214 gptbootfailed(struct dsk *dskp)
 215 {
 216
 217         if (!(gpttable[curent].ent_attr & GPT_ENT_ATTR_BOOTONCE))
 218                 return;
 219
 220         if (hdr_primary_lba > 0) {
 221                 table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
 222                 table_primary[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
 223                 gptupdate("primary", dskp, &hdr_primary, table_primary);
 224         }
 225         if (hdr_backup_lba > 0) {
 226                 table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
 227                 table_backup[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
 228                 gptupdate("backup", dskp, &hdr_backup, table_backup);
 229         }
 230 }
 231
 232 static void
 233 gptbootconv(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
 234     struct gpt_ent *table)
 235 {
 236         struct gpt_ent *ent;
 237         daddr_t slba;
 238         int table_updated, sector_updated;
 239         int entries_per_sec, nent, part;
 240
 241         table_updated = 0;
 242         entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
 243         for (nent = 0, slba = hdr->hdr_lba_table;
 244              slba < hdr->hdr_lba_table + hdr->hdr_entries / entries_per_sec;
 245              slba++, nent += entries_per_sec) {
 246                 sector_updated = 0;
 247                 for (part = 0; part < entries_per_sec; part++) {
 248                         ent = &table[nent + part];
 249                         if ((ent->ent_attr & (GPT_ENT_ATTR_BOOTME |
 250                             GPT_ENT_ATTR_BOOTONCE |
 251                             GPT_ENT_ATTR_BOOTFAILED)) !=
 252                             GPT_ENT_ATTR_BOOTONCE) {
 253                                 continue;
 254                         }
 255                         ent->ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
 256                         ent->ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
 257                         table_updated = 1;
 258                         sector_updated = 1;
 259                 }
 260                 if (!sector_updated)
 261                         continue;
 262                 bcopy(&table[nent], secbuf, DEV_BSIZE);
 263                 if (drvwrite(dskp, secbuf, slba, 1)) {
 264                         printf("%s: unable to update %s GPT partition table\n",
 265                             BOOTPROG, which);
 266                 }
 267         }
 268         if (!table_updated)
 269                 return;
 270         hdr->hdr_crc_table = crc32(0, Z_NULL, 0);
 271         hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, (const Bytef *)table,
 272             hdr->hdr_entries * hdr->hdr_entsz);
 273         hdr->hdr_crc_self = crc32(0, Z_NULL, 0);
 274         hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, (const Bytef *)hdr,
 275             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
 283 gptread_table(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
 284     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, (const Bytef *)table, nent * hdr->hdr_entsz) !=
 314             hdr->hdr_crc_table) {
 315                 printf("%s: %s GPT table checksum mismatch\n", BOOTPROG, which);
 316                 return (-1);
 317         }
 318         return (0);
 319 }
 320
 321 int
 322 gptread(struct dsk *dskp, char *buf)
 323 {
 324         uint64_t altlba;
 325
 326         /*
 327          * Read and verify both GPT headers: primary and backup.
 328          */
 329
 330         secbuf = buf;
 331         hdr_primary_lba = hdr_backup_lba = 0;
 332         curent = -1;
 333         bootonce = 1;
 334         dskp->start = 0;
 335
 336         if (gptread_hdr("primary", dskp, &hdr_primary, 1) == 0 &&
 337             gptread_table("primary", dskp, &hdr_primary, 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", dskp, &hdr_backup, table_backup) == 0) {
 358                 hdr_backup_lba = hdr_backup.hdr_lba_self;
 359                 if (hdr_primary_lba == 0) {
 360                         gpthdr = &hdr_backup;
 361                         gpttable = table_backup;
 362                         printf("%s: using backup GPT\n", BOOTPROG);
 363                 }
 364         }
 365
 366         /*
 367          * Convert all BOOTONCE without BOOTME flags into BOOTFAILED.
 368          * BOOTONCE without BOOTME means that we tried to boot from it,
 369          * but failed after leaving gptboot and machine was rebooted.
 370          * We don't want to leave partitions marked as BOOTONCE only,
 371          * because when we boot successfully start-up scripts should
 372          * find at most one partition with only BOOTONCE flag and this
 373          * will mean that we booted from that partition.
 374          */
 375         if (hdr_primary_lba != 0)
 376                 gptbootconv("primary", dskp, &hdr_primary, table_primary);
 377         if (hdr_backup_lba != 0)
 378                 gptbootconv("backup", dskp, &hdr_backup, table_backup);
 379
 380         if (hdr_primary_lba == 0 && hdr_backup_lba == 0)
 381                 return (-1);
 382         return (0);
 383 }