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 __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 "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
  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
  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
 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
 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
 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
 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
 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 }