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 } 386