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 29 #include <sys/param.h> 30 #include <sys/gpt.h> 31 32 #ifndef LITTLE_ENDIAN 33 #error gpt.c works only for little endian architectures 34 #endif 35 36 #include "zlib.h" 37 #include "drv.h" 38 #include "util.h" 39 #include "gpt.h" 40 41 #define MAXTBLENTS 128 42 43 static struct gpt_hdr hdr_primary, hdr_backup, *gpthdr; 44 static uint64_t hdr_primary_lba, hdr_backup_lba; 45 static struct gpt_ent table_primary[MAXTBLENTS], table_backup[MAXTBLENTS]; 46 static struct gpt_ent *gpttable; 47 static int curent, bootonce; 48 49 /* 50 * Buffer below 64kB passed on gptread(), which can hold at least 51 * one sector of data (512 bytes). 52 */ 53 static char *secbuf; 54 55 static void 56 gptupdate(const char *which, struct dsk *dskp, struct gpt_hdr *hdr, 57 struct gpt_ent *table) 58 { 59 int entries_per_sec, firstent; 60 daddr_t slba; 61 62 /* 63 * We need to update the following for both primary and backup GPT: 64 * 1. Sector on disk that contains current partition. 65 * 2. Partition table checksum. 66 * 3. Header checksum. 67 * 4. Header on disk. 68 */ 69 70 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz; 71 slba = curent / entries_per_sec; 72 firstent = slba * entries_per_sec; 73 bcopy(&table[firstent], secbuf, DEV_BSIZE); 74 slba += hdr->hdr_lba_table; 75 if (drvwrite(dskp, secbuf, slba, 1)) { 76 printf("%s: unable to update %s GPT partition table\n", 77 BOOTPROG, which); 78 return; 79 } 80 hdr->hdr_crc_table = crc32(0, Z_NULL, 0); 81 hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, table, 82 hdr->hdr_entries * hdr->hdr_entsz); 83 hdr->hdr_crc_self = crc32(0, Z_NULL, 0); 84 hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, hdr, 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, hdr, hdr->hdr_size) != crc) { 206 printf("%s: %s GPT header checksum mismatch\n", BOOTPROG, 207 which); 208 return (-1); 209 } 210 hdr->hdr_crc_self = crc; 211 return (0); 212 } 213 214 void 215 gptbootfailed(struct dsk *dskp) 216 { 217 218 if (!(gpttable[curent].ent_attr & GPT_ENT_ATTR_BOOTONCE)) 219 return; 220 221 if (hdr_primary_lba > 0) { 222 table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE; 223 table_primary[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED; 224 gptupdate("primary", dskp, &hdr_primary, table_primary); 225 } 226 if (hdr_backup_lba > 0) { 227 table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE; 228 table_backup[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED; 229 gptupdate("backup", dskp, &hdr_backup, table_backup); 230 } 231 } 232 233 static void 234 gptbootconv(const char *which, struct dsk *dskp, struct gpt_hdr *hdr, 235 struct gpt_ent *table) 236 { 237 struct gpt_ent *ent; 238 daddr_t slba; 239 int table_updated, sector_updated; 240 int entries_per_sec, nent, part; 241 242 table_updated = 0; 243 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz; 244 for (nent = 0, slba = hdr->hdr_lba_table; 245 slba < hdr->hdr_lba_table + hdr->hdr_entries / entries_per_sec; 246 slba++, nent += entries_per_sec) { 247 sector_updated = 0; 248 for (part = 0; part < entries_per_sec; part++) { 249 ent = &table[nent + part]; 250 if ((ent->ent_attr & (GPT_ENT_ATTR_BOOTME | 251 GPT_ENT_ATTR_BOOTONCE | 252 GPT_ENT_ATTR_BOOTFAILED)) != 253 GPT_ENT_ATTR_BOOTONCE) { 254 continue; 255 } 256 ent->ent_attr &= ~GPT_ENT_ATTR_BOOTONCE; 257 ent->ent_attr |= GPT_ENT_ATTR_BOOTFAILED; 258 table_updated = 1; 259 sector_updated = 1; 260 } 261 if (!sector_updated) 262 continue; 263 bcopy(&table[nent], secbuf, DEV_BSIZE); 264 if (drvwrite(dskp, secbuf, slba, 1)) { 265 printf("%s: unable to update %s GPT partition table\n", 266 BOOTPROG, which); 267 } 268 } 269 if (!table_updated) 270 return; 271 hdr->hdr_crc_table = crc32(0, Z_NULL, 0); 272 hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, table, 273 hdr->hdr_entries * hdr->hdr_entsz); 274 hdr->hdr_crc_self = crc32(0, Z_NULL, 0); 275 hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, hdr, 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, const uuid_t *uuid, struct dsk *dskp, 284 struct gpt_hdr *hdr, 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, table, nent * hdr->hdr_entsz) != 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 321 gptread(const uuid_t *uuid, 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", uuid, dskp, &hdr_primary, 337 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", uuid, dskp, &hdr_backup, 358 table_backup) == 0) { 359 hdr_backup_lba = hdr_backup.hdr_lba_self; 360 if (hdr_primary_lba == 0) { 361 gpthdr = &hdr_backup; 362 gpttable = table_backup; 363 printf("%s: using backup GPT\n", BOOTPROG); 364 } 365 } 366 367 /* 368 * Convert all BOOTONCE without BOOTME flags into BOOTFAILED. 369 * BOOTONCE without BOOTME means that we tried to boot from it, 370 * but failed after leaving gptboot and machine was rebooted. 371 * We don't want to leave partitions marked as BOOTONCE only, 372 * because when we boot successfully start-up scripts should 373 * find at most one partition with only BOOTONCE flag and this 374 * will mean that we booted from that partition. 375 */ 376 if (hdr_primary_lba != 0) 377 gptbootconv("primary", dskp, &hdr_primary, table_primary); 378 if (hdr_backup_lba != 0) 379 gptbootconv("backup", dskp, &hdr_backup, table_backup); 380 381 if (hdr_primary_lba == 0 && hdr_backup_lba == 0) 382 return (-1); 383 return (0); 384 } 385